K, fine.
![Cheesy :D](https://elementscommunity.org/forum/Smileys/solosmileys/cheesy.gif)
Umm... Mantis actually seems a bit overpowered. Very useful ability for only 2 life gives itself +1/+1, and it starts off with 5/5. It's basically a more powerful Arctic Squid - its ability is weaker but cheaper, and can also strengthen it. Also, its sheer attack power is great- after all, Abomination has the same stats as it with no ability, and costs the same amount. I would make his ability cost 3, nerf his stats, make him rare, or a combination thereof.
Vomit actually should be pretty acidic, because it comes from your stomach. Well, I don't know, I'm not a biologist. But vomiting can cause others to vomit at the sight of it, so how about this:
Gastric Blast: Spell (4 Life Quanta)
Deal 2 damage to target creature. Give it the ability "Gastric Blast" for 3 of its quanta.