John Wall smiled late Saturday night as he explained the relentless, aggressive, high-leaping, trash-talking model of himself that has been popping up on YouTube videos all summer. It was all over the floor at Trinity University — where Wall scored 28 points and helped the local Goodman League defeat the Los Angeles-based Drew League, 135-134, in an East-West summer league showcase for bragging rights. “I’m back. I’m back, man. I’m back to myself,” Wall said after an electrifying performance.