Special Abilities

Hey all. I'm trying to decide how to value certain special abilities. Specifically venomous breath, + crit, and + agility (increased speed). Which of these do you see as most valuable? I'm not even entirely sure what the speed bonus does. Thanks for the input.

Venomous Breath decreases hp per turn. (Not sure how much)

I personally don't find agi rate that effective. However, even though its +5% speed, I think it makes you attack more frequently. I would personally choose agi though over crit because crit its a % which is unstable imo. Correct me if i'm wrong.

Hihi

Increase in Agi will increase the chance of your opponent to miss, not that you will attack faster hihi.
Venomous breath deals damage to an affected monster when it is the monster turns to attack. (The higher the level of your monster with Breath, the higher the poison damage.)
Critical damage-Deals the highest possible damage your monster could hit.

Now decide hihi.