When thinking of candidates for Galactic Legend status, the insidious mastermind behind literally everything in the prequels has to come to mind, no?
I imagine a strong leader who lurks in the shadows to manipulate his team rather than personally involve himself. The most interesting thing about his kit could be his ability to synergize uniquely with Galactic Republic, Separatists, and Sith.
In these regards, he could be very similar to C-3PO (with abilities affecting each faction differently, possibly only one active at a time since he couldn’t very well lead two conflicting armies in one team).
Just an idea from a fan of The Senate