That's a scary potion.
I like the idea, but it would need to be implemented differently, otherwise you drink all of them right before the game ends.
Yeah or make it just for next wave,not survival,with x10 power,so player can drink 10x before challenge for example and this potion can also make enemy walk faster
This could be a prophecy (unique? Or, if dangerous, then legendary).
I'm thinking something like this:
Prophesy of Mastery
Until a challenge creep survives, each challenge creep defeated gives creeps 5% more health and increases damage to Vir by 5%.
- - -
One option to not make this suicidal is to make the extra health a different color (maybe gray instead of green), and that part of the health bar doesn't deal damage to the player's wizard health.
It would still decrease xp and items if creeps leaked, but it wouldn't increase the difficulty of the bonus round. This means the chance of meeting Vir stays roughly the same as before.