They would be very quiet maniacs. Played on 1. Fed through 17 wah-wah pedals.
Also, we need some post-rock pyrotechnics. So, slow and epic. For example: the lead guitarist wears a pair of trousers made from cigarette papers (rolled invidually for each show by a dedicated team of proffessional stoners). In the middle of one song, he gets a very epic, majestic, emotional 9 minute long guitar solo at the start of which is trousers ignite from the crotch and slowly burn away throughout.
Another option for stage theatrics would be to just put on a tape of say, four of our songs, then all go on stage dressed in leather jackets and play dead kennedys, bad brains and SOD covers complete with stage dives and inter-band moshing, but without our instruments or mics plugged in.
Just the tape playing.