The art looks pretty sweet. Its hard to see the greek letter Xi though.
Mechanics wise this seems a little on the OP side. 3 card draw is a bit too powerful to couple with dealing damage equal to total cost.
If you drew 3 miracles that would deal 45 damage. 4 card draw is even worse. The relatively high cost and discard help a little but it just doesn't seem like enough.
Consider what would happen in a deck filled with mainly these, heavy cost cards, and just enough pillars / towers to cover. E.g. Dragons. Not only do you tear the opponent apart with the initial damage, but you get a bunch of heavy hitter cards on top of it.
One option would be to use the wording:"Draw 3 cards. Opponent takes damage based on thier combined cost. Discard a card."
Then you can scale the damage dealt to keep otk potential in check. (Something like catapult, but maybe a little stronger)
Alternatively, have the effect only deal damage based on the discarded card. E.g. you get 3 cards, you pick 2 to keep and one to fling at the enemy as damage. That way you get some effect from all of them and it forces the player to choose between future utility or an immediate damage output.
Another consideration is that the ability should take upgrade status into account if it is based on card cost. Upgraded cards should be worth at least as much as the unupped version (after all, the player shelled out 1500
for it). Unfortunately, many upped cards have a lower cost.
The card is interesting but I think it could use a little work before hitting crucible.