Advance Voss

On the front side of Voss, the advance mode says Reduce damage dealt by heroes by 1.

Does that mean that Fanatic deals herself 1-1=0 damage for using Chastise? And for similar situations with other heroes dealing themselves damage, do they all get reduced by 1? I.e. Wrest the Mind.

Yes

Also kinda screws over Absolute Zero’s powers.

Cool. That will allow me to Chastise one of the minions indefinitely to prevent Voss from flipping and keep his protection at -3 (-1 from Advance and -2 from 1 minion). The rest of the team will attack Voss directly with 4 damage and above.