I did further simulations. This time my simulated god will save up Might for a specified number of turns and spend it all on a Holy Site when the cooldown expires.
By just spending the one turn of Might on Holy Sites, I cut down the time to level 100 to 34 Turns. By Turn 9 our god had reached Level 11 and had 2 Holy Sites. This is only one level ahead at this point, but from turn 8 onwards it went up two levels per turn. The fourth Holy Site, built Turn 18 Level 28, boosted the rate from 2-3 levels per turn to a fairly consistent 4 levels per turn. Holy Site number 5 (Turn 30, Level 73) got us to 7 levels per turn.
[hider=Simulation 1]
**Turn 2 start**
Level: 2, Might: 5, M/T: 5, Holy Sites: 0
!! Built a Holy Site with 5 Might
Level: 2, Might: 0, M/T: 7.5, Holy Sites: 1
**Turn 3 start**
Level: 2, Might: 7.5, M/T: 7.5, Holy Sites: 1
! Levelled up to Level 3
Level: 3, Might: 3.5, M/T: 8.5, Holy Sites: 1
**Turn 4 start**
Level: 3, Might: 12.0, M/T: 8.5, Holy Sites: 1
! Levelled up to Level 4
! Levelled up to Level 5
Level: 5, Might: 1.0, M/T: 10.5, Holy Sites: 1
**Turn 5 start**
Level: 5, Might: 11.5, M/T: 10.5, Holy Sites: 1
! Levelled up to Level 6
Level: 6, Might: 1.5, M/T: 11.5, Holy Sites: 1
**Turn 6 start**
Level: 6, Might: 13.0, M/T: 11.5, Holy Sites: 1
!! Built a Holy Site with 13.0 Might
Level: 6, Might: 0, M/T: 18.0, Holy Sites: 2
**Turn 7 start**
Level: 6, Might: 18.0, M/T: 18.0, Holy Sites: 2
! Levelled up to Level 7
Level: 7, Might: 8.0, M/T: 19.0, Holy Sites: 2
**Turn 8 start**
Level: 7, Might: 27.0, M/T: 19.0, Holy Sites: 2
! Levelled up to Level 8
! Levelled up to Level 9
Level: 9, Might: 7.0, M/T: 21.0, Holy Sites: 2
**Turn 9 start**
Level: 9, Might: 28.0, M/T: 21.0, Holy Sites: 2
! Levelled up to Level 10
! Levelled up to Level 11
Level: 11, Might: 3.0, M/T: 23.0, Holy Sites: 2
**Turn 10 start**
Level: 11, Might: 26.0, M/T: 23.0, Holy Sites: 2
!! Built a Holy Site with 26.0 Might
Level: 11, Might: 0, M/T: 36.0, Holy Sites: 3
**Turn 11 start**
Level: 11, Might: 36.0, M/T: 36.0, Holy Sites: 3
! Levelled up to Level 12
! Levelled up to Level 13
Level: 13, Might: 6.0, M/T: 38.0, Holy Sites: 3
**Turn 12 start**
Level: 13, Might: 44.0, M/T: 38.0, Holy Sites: 3
! Levelled up to Level 14
! Levelled up to Level 15
Level: 15, Might: 14.0, M/T: 40.0, Holy Sites: 3
**Turn 13 start**
Level: 15, Might: 54.0, M/T: 40.0, Holy Sites: 3
! Levelled up to Level 16
! Levelled up to Level 17
! Levelled up to Level 18
Level: 18, Might: 9.0, M/T: 43.0, Holy Sites: 3
**Turn 14 start**
Level: 18, Might: 52.0, M/T: 43.0, Holy Sites: 3
! Levelled up to Level 19
! Levelled up to Level 20
! Levelled up to Level 21
Level: 21, Might: 2.0, M/T: 46.0, Holy Sites: 3
**Turn 15 start**
Level: 21, Might: 48.0, M/T: 46.0, Holy Sites: 3
! Levelled up to Level 22
! Levelled up to Level 23
Level: 23, Might: 8.0, M/T: 48.0, Holy Sites: 3
**Turn 16 start**
Level: 23, Might: 56.0, M/T: 48.0, Holy Sites: 3
! Levelled up to Level 24
! Levelled up to Level 25
Level: 25, Might: 16.0, M/T: 50.0, Holy Sites: 3
**Turn 17 start**
Level: 25, Might: 66.0, M/T: 50.0, Holy Sites: 3
! Levelled up to Level 26
! Levelled up to Level 27
! Levelled up to Level 28
Level: 28, Might: 6.0, M/T: 53.0, Holy Sites: 3
**Turn 18 start**
Level: 28, Might: 59.0, M/T: 53.0, Holy Sites: 3
!! Built a Holy Site with 59.0 Might
Level: 28, Might: 0, M/T: 82.5, Holy Sites: 4
**Turn 19 start**
Level: 28, Might: 82.5, M/T: 82.5, Holy Sites: 4
! Levelled up to Level 29
! Levelled up to Level 30
! Levelled up to Level 31
! Levelled up to Level 32
Level: 32, Might: 2.5, M/T: 86.5, Holy Sites: 4
**Turn 20 start**
Level: 32, Might: 89.0, M/T: 86.5, Holy Sites: 4
! Levelled up to Level 33
! Levelled up to Level 34
! Levelled up to Level 35
! Levelled up to Level 36
Level: 36, Might: 9.0, M/T: 90.5, Holy Sites: 4
**Turn 21 start**
Level: 36, Might: 99.5, M/T: 90.5, Holy Sites: 4
! Levelled up to Level 37
! Levelled up to Level 38
! Levelled up to Level 39
! Levelled up to Level 40
Level: 40, Might: 19.5, M/T: 94.5, Holy Sites: 4
**Turn 22 start**
Level: 40, Might: 114.0, M/T: 94.5, Holy Sites: 4
! Levelled up to Level 41
! Levelled up to Level 42
! Levelled up to Level 43
! Levelled up to Level 44
! Levelled up to Level 45
Level: 45, Might: 14.0, M/T: 99.5, Holy Sites: 4
**Turn 23 start**
Level: 45, Might: 113.5, M/T: 99.5, Holy Sites: 4
! Levelled up to Level 46
! Levelled up to Level 47
! Levelled up to Level 48
! Levelled up to Level 49
! Levelled up to Level 50
Level: 50, Might: 13.5, M/T: 104.5, Holy Sites: 4
**Turn 24 start**
Level: 50, Might: 118.0, M/T: 104.5, Holy Sites: 4
! Levelled up to Level 51
! Levelled up to Level 52
! Levelled up to Level 53
Level: 53, Might: 28.0, M/T: 107.5, Holy Sites: 4
**Turn 25 start**
Level: 53, Might: 135.5, M/T: 107.5, Holy Sites: 4
! Levelled up to Level 54
! Levelled up to Level 55
! Levelled up to Level 56
! Levelled up to Level 57
Level: 57, Might: 15.5, M/T: 111.5, Holy Sites: 4
**Turn 26 start**
Level: 57, Might: 127.0, M/T: 111.5, Holy Sites: 4
! Levelled up to Level 58
! Levelled up to Level 59
! Levelled up to Level 60
! Levelled up to Level 61
Level: 61, Might: 7.0, M/T: 115.5, Holy Sites: 4
**Turn 27 start**
Level: 61, Might: 122.5, M/T: 115.5, Holy Sites: 4
! Levelled up to Level 62
! Levelled up to Level 63
! Levelled up to Level 64
! Levelled up to Level 65
Level: 65, Might: 2.5, M/T: 119.5, Holy Sites: 4
**Turn 28 start**
Level: 65, Might: 122.0, M/T: 119.5, Holy Sites: 4
! Levelled up to Level 66
! Levelled up to Level 67
! Levelled up to Level 68
! Levelled up to Level 69
Level: 69, Might: 2.0, M/T: 123.5, Holy Sites: 4
**Turn 29 start**
Level: 69, Might: 125.5, M/T: 123.5, Holy Sites: 4
! Levelled up to Level 70
! Levelled up to Level 71
! Levelled up to Level 72
! Levelled up to Level 73
Level: 73, Might: 5.5, M/T: 127.5, Holy Sites: 4
**Turn 30 start**
Level: 73, Might: 133.0, M/T: 127.5, Holy Sites: 4
!! Built a Holy Site with 133.0 Might
Level: 73, Might: 0, M/T: 194.0, Holy Sites: 5
**Turn 31 start**
Level: 73, Might: 194.0, M/T: 194.0, Holy Sites: 5
! Levelled up to Level 74
! Levelled up to Level 75
! Levelled up to Level 76
! Levelled up to Level 77
! Levelled up to Level 78
! Levelled up to Level 79
Level: 79, Might: 14.0, M/T: 200.0, Holy Sites: 5
**Turn 32 start**
Level: 79, Might: 214.0, M/T: 200.0, Holy Sites: 5
! Levelled up to Level 80
! Levelled up to Level 81
! Levelled up to Level 82
! Levelled up to Level 83
! Levelled up to Level 84
! Levelled up to Level 85
! Levelled up to Level 86
Level: 86, Might: 4.0, M/T: 207.0, Holy Sites: 5
**Turn 33 start**
Level: 86, Might: 211.0, M/T: 207.0, Holy Sites: 5
! Levelled up to Level 87
! Levelled up to Level 88
! Levelled up to Level 89
! Levelled up to Level 90
! Levelled up to Level 91
! Levelled up to Level 92
! Levelled up to Level 93
Level: 93, Might: 1.0, M/T: 214.0, Holy Sites: 5
**Turn 34 start**
Level: 93, Might: 215.0, M/T: 214.0, Holy Sites: 5
! Levelled up to Level 94
! Levelled up to Level 95
! Levelled up to Level 96
! Levelled up to Level 97
! Levelled up to Level 98
! Levelled up to Level 99
! Levelled up to Level 100
Level: 100, Might: 5.0, M/T: 221.0, Holy Sites: 5
[/hider]

The best time I can get is 25 Turns, at 4 or 5 turns of savings per Holy Site. At 4 turns of savings per Holy Site, that the first 3 Holy Sites, taking until Turn 10 to build, occupy its entire spending. But with that Might Production it can then leap the levels until it reaches 100.
[hider=Best Simulation]
**Turn 2 start**
Level: 2, Might: 5, M/T: 5, Holy Sites: 0
!! Built a Holy Site with 5 Might
Level: 2, Might: 0, M/T: 7.5, Holy Sites: 1
**Turn 3 start**
Level: 2, Might: 7.5, M/T: 7.5, Holy Sites: 1
**Turn 4 start**
Level: 2, Might: 15.0, M/T: 7.5, Holy Sites: 1
**Turn 5 start**
Level: 2, Might: 22.5, M/T: 7.5, Holy Sites: 1
**Turn 6 start**
Level: 2, Might: 30.0, M/T: 7.5, Holy Sites: 1
!! Built a Holy Site with 30.0 Might
Level: 2, Might: 0, M/T: 22.5, Holy Sites: 2
**Turn 7 start**
Level: 2, Might: 22.5, M/T: 22.5, Holy Sites: 2
**Turn 8 start**
Level: 2, Might: 45.0, M/T: 22.5, Holy Sites: 2
**Turn 9 start**
Level: 2, Might: 67.5, M/T: 22.5, Holy Sites: 2
**Turn 10 start**
Level: 2, Might: 90.0, M/T: 22.5, Holy Sites: 2
!! Built a Holy Site with 90.0 Might
Level: 2, Might: 0, M/T: 67.5, Holy Sites: 3
**Turn 11 start**
Level: 2, Might: 67.5, M/T: 67.5, Holy Sites: 3
! Levelled up to Level 3
! Levelled up to Level 4
! Levelled up to Level 5
! Levelled up to Level 6
! Levelled up to Level 7
! Levelled up to Level 8
! Levelled up to Level 9
! Levelled up to Level 10
Level: 10, Might: 2.5, M/T: 75.5, Holy Sites: 3
**Turn 12 start**
Level: 10, Might: 78.0, M/T: 75.5, Holy Sites: 3
! Levelled up to Level 11
! Levelled up to Level 12
! Levelled up to Level 13
! Levelled up to Level 14
! Levelled up to Level 15
Level: 15, Might: 3.0, M/T: 80.5, Holy Sites: 3
**Turn 13 start**
Level: 15, Might: 83.5, M/T: 80.5, Holy Sites: 3
! Levelled up to Level 16
! Levelled up to Level 17
! Levelled up to Level 18
! Levelled up to Level 19
! Levelled up to Level 20
Level: 20, Might: 8.5, M/T: 85.5, Holy Sites: 3
**Turn 14 start**
Level: 20, Might: 94.0, M/T: 85.5, Holy Sites: 3
! Levelled up to Level 21
! Levelled up to Level 22
! Levelled up to Level 23
! Levelled up to Level 24
Level: 24, Might: 14.0, M/T: 89.5, Holy Sites: 3
**Turn 15 start**
Level: 24, Might: 103.5, M/T: 89.5, Holy Sites: 3
**Turn 16 start**
Level: 24, Might: 193.0, M/T: 89.5, Holy Sites: 3
**Turn 17 start**
Level: 24, Might: 282.5, M/T: 89.5, Holy Sites: 3
**Turn 18 start**
Level: 24, Might: 372.0, M/T: 89.5, Holy Sites: 3
!! Built a Holy Site with 372.0 Might
Level: 24, Might: 0, M/T: 275.5, Holy Sites: 4
**Turn 19 start**
Level: 24, Might: 275.5, M/T: 275.5, Holy Sites: 4
! Levelled up to Level 25
! Levelled up to Level 26
! Levelled up to Level 27
! Levelled up to Level 28
! Levelled up to Level 29
! Levelled up to Level 30
! Levelled up to Level 31
! Levelled up to Level 32
! Levelled up to Level 33
! Levelled up to Level 34
! Levelled up to Level 35
! Levelled up to Level 36
! Levelled up to Level 37
Level: 37, Might: 15.5, M/T: 288.5, Holy Sites: 4
**Turn 20 start**
Level: 37, Might: 304.0, M/T: 288.5, Holy Sites: 4
! Levelled up to Level 38
! Levelled up to Level 39
! Levelled up to Level 40
! Levelled up to Level 41
! Levelled up to Level 42
! Levelled up to Level 43
! Levelled up to Level 44
! Levelled up to Level 45
! Levelled up to Level 46
! Levelled up to Level 47
! Levelled up to Level 48
! Levelled up to Level 49
! Levelled up to Level 50
! Levelled up to Level 51
Level: 51, Might: 14.0, M/T: 302.5, Holy Sites: 4
**Turn 21 start**
Level: 51, Might: 316.5, M/T: 302.5, Holy Sites: 4
! Levelled up to Level 52
! Levelled up to Level 53
! Levelled up to Level 54
! Levelled up to Level 55
! Levelled up to Level 56
! Levelled up to Level 57
! Levelled up to Level 58
! Levelled up to Level 59
! Levelled up to Level 60
! Levelled up to Level 61
Level: 61, Might: 16.5, M/T: 312.5, Holy Sites: 4
**Turn 22 start**
Level: 61, Might: 329.0, M/T: 312.5, Holy Sites: 4
! Levelled up to Level 62
! Levelled up to Level 63
! Levelled up to Level 64
! Levelled up to Level 65
! Levelled up to Level 66
! Levelled up to Level 67
! Levelled up to Level 68
! Levelled up to Level 69
! Levelled up to Level 70
! Levelled up to Level 71
Level: 71, Might: 29.0, M/T: 322.5, Holy Sites: 4
**Turn 23 start**
Level: 71, Might: 351.5, M/T: 322.5, Holy Sites: 4
! Levelled up to Level 72
! Levelled up to Level 73
! Levelled up to Level 74
! Levelled up to Level 75
! Levelled up to Level 76
! Levelled up to Level 77
! Levelled up to Level 78
! Levelled up to Level 79
! Levelled up to Level 80
! Levelled up to Level 81
! Levelled up to Level 82
Level: 82, Might: 21.5, M/T: 333.5, Holy Sites: 4
**Turn 24 start**
Level: 82, Might: 355.0, M/T: 333.5, Holy Sites: 4
! Levelled up to Level 83
! Levelled up to Level 84
! Levelled up to Level 85
! Levelled up to Level 86
! Levelled up to Level 87
! Levelled up to Level 88
! Levelled up to Level 89
! Levelled up to Level 90
! Levelled up to Level 91
! Levelled up to Level 92
! Levelled up to Level 93
Level: 93, Might: 25.0, M/T: 344.5, Holy Sites: 4
**Turn 25 start**
Level: 93, Might: 369.5, M/T: 344.5, Holy Sites: 4
! Levelled up to Level 94
! Levelled up to Level 95
! Levelled up to Level 96
! Levelled up to Level 97
! Levelled up to Level 98
! Levelled up to Level 99
! Levelled up to Level 100
Level: 100, Might: 159.5, M/T: 351.5, Holy Sites: 4
[/hider]