gonna sound like a cop out, but for me it's a toss up. Wrestling wise I'd have to go with Styles, but character wise I'd go with Jericho. Especially his 08-10 heel run. That's when he fully turned himself into a legitimate main eventer, not like in '01 when they slapped the world titles on him and did nothing with him.
Therefor I'm gonna go by kayfabe rules. Jericho got to pin Styles twice, while AJ pinned Jericho 3 times and made him tap out once, as far as I remember. So Styles wins by unanimous decision