I've always loved bow users, and Trey can be deadly. Yeah, he's a bit useless against some enemies, but if you can time his movements right, he's one of the most useful units.
Runners up are Ace (teleporting and cards are awesome), Jack (he's so strong), Eight (I didn't think I'd like him, but he's great), and Deuce (she's an expert boss killer). --- 3DS FC: 4596 9948 4995 (Fighting Safari with Machoke, Throh, and Riolu) Shiny Value: 695 (PM me to hatch your shiny- I won't ask for anything in return!)
Trey gets a great move called shield&smash for those close range fights. It makes him quite a bit more useful :) --- "Well if you think chickens can fly, we better pull up wikipedia." - S. Healy PS4 FAQs http://www.gamefaqs.com/boards/691087-playstation-4/67619422