Note: All of this is for Advanced Mode.
Against the villains we have for the App, Unity is nuts. There's a fair amount of different heroes being of different quality vs. the 5/7 (if we count alternates) villains we have, like Visionary being amazing against Dawn, Voss, and Baron Blade, but not having much to do with either version of Omnitron or Promo Blade. The same can largely be said for Absolute Zero against a villain with equipment destruction and a location that destroys equipment... or either Blade, the original which makes games go too quickly and the latter who destroys all of A/Z's stuff too effectively. Admittedly, these are extreme examples, but each also proves the point well. Some others are always good, but usually dependent on their teams for how good (Legacy has less weight if your team includes Ra and Haka than if it does Tempest).
Neither of these cases applies for Unity. If you aren't nuts about Unity's own health, she will get set up. Unless you have very bad luck with Swift Bot then, she will soon become a power house. Once that's the case, she's capable of, within 3 turns, dealing like 15 damage per turn, of different types, to either 1 target or many, while also being able to nuke ongoings and enviornments or just make sure the nastier ones just hit the enemy. This isn't the case in the full game, as several villains are anathema to her, constantly nailing and eliminating her bots, but for what we have now in the App, she's just nuts. She rips apart everyone, in every setting that I've found, needing very little support (in fact, basically everyone offers her some sort of help).
Aside: If not for damage reduction, TLT would be right there... there are a TON of ways to mitigate that one weakness though - Twist the Ether, Alternate Bunker, Imbued Fire, Galvanize or Inspiring Presence, the Wagon or Obsidian Field. Still, it is a weakness.
