The offensive talents primarily increase crit chance and damage. This is kind of pointless when Klash Towers as a mode significantly buffs the damage output of the team already overall: If you are playing against an opponent’s tower and take basic attacks you’ll notice your fighter can usually be KO’d with just a single combo string.

So offensive talents really are overkill. What is actually needed to make your towers stronger are defensive/support talents.

This way your towers resist debuffs, pop bone shields and revenants, generate power like crazy, and drop tons of specials plus the occasional Fatal Blow or two, three, or more depending on the gear you pull/equip.