User blog comment:XDarkRepulse/Need help for UoC/@comment-26331700-20160329022427

Xenon, Xenon and Estia are collaboration units, so I don't think you can ask for that.

I would go for either Zenia or Tridon.

Tridon if you want a semi mitigator leader and defensive bb/sbb/ubb.

Go with Zenia if you want single target ubb nuking and damage utility, although she's slowly sliding off the current meta-game because she's outclassed.

Really depends on what you need.