OK your synchro is written up incorrecty, as you forgot the summon requirement, as well as the card text is worded so odd in comparison to all other effects.

Here is the corrected card text + some good edits

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1 tuner + 1 or more non-tuner monsters (limit the attribute or monster type, or lessen the monsters attack, or you could add another cost to the add to hand effect)

When this card is special summoned, destroy all other monsters you control. This card cannot be destroyed by battle.
When this card attacks or is attacked, you can target 1 card in your graveyard, add it to your hand. When this card is destroyed, discard all cards in your hand.
3000/2500

a version that makes it less OP:

1 tuner + 1 or more non-tuner monsters

When this card is special summoned, destroy all other monsters you control. This card cannot be destroyed by battle.
Once per turn, during the end phase, if this card attacked, or was attacked this turn, you can target 1 card in your graveyard, place it on top of your deck.
If this card would be destroyed, you can discard all cards in your hand instead (min. 1) This effect of "Luminas, the chaos fairy" can only be used once while this card is face-up on the field.
2800/2500

This version makes it so you cant just spam the effect and an effect that prevents the cards destruction (I tend to think of its uses in any deck, not just yours)
the second effect is a nice little add on that allows you to at least get the effect once, but does not allow that effect to go through when it dies.
The limited recycle just makes it so it isn't an instant plus 1, which if you look at all draw effects, is a lot. 
The lowered attack is just so it isn't a really good 3000 beater that can transfer into a really good 4000 beater, though 2800 is only 200 less, and still decent.

The //assault mode version, please lower its attack to 3500 or something, cuz 4000 is too good for a piercing attack beater. 0 def monster? you have half life now, GG.
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STAR SERAPHS ARE MINE (I am also using rank-up, but i might have to change the names)