I like where your going with this, but all the cards basically have the same mechanics which is a bit..repetetive.
like for example, instead of just absorbing hp
why not make a creature with ability like:
stat: X/5
absorbs 4 hp per turn:
2: Blood rage: X = total hp absorbed, divided by 3 (rounded down),
one use.
(this creature absorbs your hp)
(the ability costs 2 quanta)
just an example.
what im trying to say is, to stick with the theme of hp absorption but apply different mechanics.
to make it more interesting.