what if it had a meter that built up, that when activated, it can launch a lightning bolt that will slow the player that it hits, sets them on fire for a couple of seconds, and do maybey 15 damage.

+build lighting meter to launch lighting bolt (see above)
+crits on wet players

- -10% damage penalty
- -10% attack speed

lol

it would be cool if it would stun players on crit,

Considering the origin (Frankenstein) I'm thinking something along the lines of the Vitasaw's 'Collecting organs' but with limbs and stuff, providing some form of bonus, maybe increasing the Medic's stats (Health, Melee damage, Afterburn immunity etc)