Criticism is a tough job mate! It's challenging work, indoors... I guarantee you won't get bored, as as long as there are two people left on the planet, someone is going to have an idea.
Dracula: Costly mobspammer, but Mono. Seeing the stats on both I'd lower this one's initial cost.
Minion: Particularly weak member of mobcrowd.
Ant Queen: More mobspammer? And a much cheaper one, at that. I'd make this ability Life - you're creating new living beings. Insects.
Ant: Oh come on, Ants are natural things to give Swarm to. I won't be lining those until you make them Swarm. Also, the upgrade is so much more powerful.
Seduction: How can a spell last turns? Also... well... what was first, this or Despair? They seem to be doing the same thing.
Scramble: Permanent mutation. Old beaten concept, your method of putting it is also typical. C, now sit back down...
Hacker: Okay, what is this meant to be about? Un-theme-fitting space-up-taker. Seems like a cheap idea ripoff of Aflatoxin. This, and HAAAAAAAXOR himself is pretty hard to take out himself... too hard, even.
Bug: The MaliCell does nothing... fix it!
System Error: That's a perticularly nice concept, but could be too strong.
Ninja Star: So, it'd be dealing roughly like... wait, does every pillar count as a card? ...like 15 damage every turn if yes, not so costly, costs you life after long enough... seems fairly alright, or a bit too strong.
Pistol: 24 damage in a cheap sixpack and then it's useless. Ookay... also, name. Does it have to be this?
Dragon Egg: 4 Time + frail creature turn => creature with about 5-6 attack and low HP, as well as paradoxablity, in most cases. Not worth it.
Power Surge: Randomly change half of me? DO NOT WANT Also, er... the name-element-effect combination doesn't seem right to me, but flock this. Also, costly. Too costly for the effect. Either it does nearly nothing or the enemy still has pretty many quanta to pay for stuff afterwards.
Health Generator: It's alright, I guess.
Magic Blocker: Also fairly alright. Prevents you from Armoring. Wait, also a lasting spell? You can't do this, you know...