I would aim to be like BJ Penn (him in his prime as compared to his peers). Can do everything, fucks people up, good technique, creative, would fight bigger guys. No cringey trashtalk, but bringing the excitement pre fight. finding ways to win. But, alas, prime BJ is a freak talent and has crazy reflexes. Also I'm totally not as flexible. but one can dream...
I would also aim to be a cardio machine...
If I could wish for anything I would most likely want to be like prime Chuck: always get back up, never mentally quit and blow fools up, and have the crazy celebration after a good ko.
So Chuck's reach & chin or BJ's reflexes and other gifts I can't control but I would strive NOT to be some guy with a weakness that always gets him. I'd try to work on things and improve like Bas Rutten with the the grappling, Cejudo with the striking, GSP with the takedowns etc. (Ronda with the elite boxing, hehe)
And everytime I fought in a foreign country I would try to learn to say a few things in the language there.
As a coach I'd have a guy like Henry Hooft, Master Cordeiro, Duke Roufus or Jason Parillo for the character rather than some calm guy with a safe gameplan or Javier Mendez who I found to have an authority complex in interviews that I saw (wouldn't want the guys from AKA around me anyway. great successes but not my kinda dudes)