He never used to be Tran. I used to watch him regularly back in the day, he was funny but just funny.
Vic Reeves was much funnier, and Gerry Sadowitz was the funniest I ever saw.
I think the TV gimmick allowed him to adopt a character and that gave him enough confidence to believe he was funny and his material improved accordingly.
Last couple of times I have seen him he has almost killed me, I thought I was going to turn inside out I was laughing so hard.
Genius.