those characters bios suck btw...
roland- creates small deployable sentry guns which project small shields you can duck behind, best at assault rifles
lilith- teleports into a different dimension, causing two explosions. best at elemental weaponry
brick- punches stuff, gets angry and extremely resistant to dmg, best with explosives and his fists
mordecai- can summon a small bird to attack his enemies, best with sniper rifles and revolvers