mindgate: u get 1 of ur opponents card, for
hourglass: u get ur next card in the deck, for
both above can only be used if a have the specific quanta in ur deck
Shard of Insight: u get a card of ur choice for 0, can be used in ANY deck, and is VERY OP in mono decks
maybe if u dont draw in the next turn, it could be better (but that would make not decking out much,much easier)
"You get, at most 8 random cards of your mark's element to choose between" - u realise that there r ~15 cards for each element? if u use 2-3 of this shard, u can draw whatever u need (ig. darkness: steel sg in every turn, for gravity spam black holes+momentum all ur creatures+summon oty when u feel like it etc.)
not speaking about rares/pillars/nymphs (i guess u shouldnt be able to draw them by the way)
i dont get how cant u see thats VERY OP
make it a spell, that could balance it a bit