The effect definitely needs to be an activated one with a cost - see Mindgate/Electrum Hourglass/Sundial which all deal with 'drawing' cards.
I can see this card being a staple in Entropy decks, and it might even be extremely overpowered. Generally, cards which allow you to draw outside of your deck are very, very strong from my experience in CCGs. Mindgate is an underwhelming card because it requires you to have a ready supply of Aether quanta and the card you draw will be random. It definitely needs to be a random spell, because a card which gives you card advantage (that is usable) without hindering your deck size will be very strong.
Idea-wise, I think it is very fitting with the theme of Entropy.