ok those custom cards. HOLY FUCKING GOD WTF THATS OP. my brain hurts of the OP-ness (say that [not a] word out loud a few times)

Abyss of infestation: 500 atk gain? with an extra bit of archetype synergy, oh and a recycle effect, in exchange for your "Normal draw during your draw phase" (correct phrasing)

all of the steelswarms you have use effects that benefit from the extra synergy (even if it is just more targets for tributing)
 this makes the rest of it a bit crazy to me. I have never played Lswarms, but with any deck giving all of your monsters a plus 500 atk and the ability to get them back from your grave. Unless you can show me a legit reason this isn't OP, put some sort of cost/ lower the benefit.

Goliath....holy fuck that's OP you have to tribute 3 monsters to summon it? no big deal, your deck is basically built to get this thing out, with the cluster and whatnot.
Imagine this thing. if you have that field spell, you get a board wipe, otherwise it is a once per turn Harpies feather duster/Raigeki. The attack is outrageous, no matter how you look at it. the best 3 level (4 or lower) XYZ monsters have at most 3950 atk (normal monster) the other, 2800 with a reasonable effect that is not OP, given its cost and stats. 

Goliath needs not just an effect change, but a stat reduction.

[hider=Goliath but more fair]

Level 10

This card must first me normal summoned by tributing 3 "steelswarm" monsters you control. If you control a face up "Abyss of infestation" this cards normal summon cannot be negated. If this card is normal summoned while "Abyss of infestation" is on the field, you can pay 1000 life points, destroy all other cards on the field. You cannot conduct your battle phase the turn this card is summoned.
Once per turn, you can remove from play 1 card in your hand, then activate the following effect that corresponds to the card-type of the removed from play card.

Spell: Destroy all face-up spell and trap cards on the field.
Trap: Destroy all set spell and trap cards on the field.
Monster: Destroy all face-up monsters on the field, except this card.

This card cannot attack the turn this effect of " Goliath, the first steelswarm" is activated. You can only control 1 "Goliath, the first steelswarm"
2900/0

again, i dont play lswarms, so i dont know if that would even work, but given the other cards, this should be fine, atleast stat-wise.
[/hider]

I was going to complain about clusters effect (defense is kind of high) but i see with the obvious intention for tributing it is kind of needed. though i do think it needs some sort of a small cost.

And done. That took me forever to write up...