Cosmos (the second character) being abusable. To put it very simply, her third ability instantly removes cooldown on her first two abilities on top of letting her use those abilities twice if she casted the third ability a second time. Thats on top of the third ability' cooldown being reduced by one everytime Cosmos recieves a buff from an ally. Just keep spamming buffs and hilarity ensues. Edit: Completely forgot to mention that her third ability also grants her a permanent buff that lets her do a charge attack twice!