Can't believe I'm agreeing with
@markg171 but Merab is the exception that makes the rule. We haven't seen him even BEGIN to slow down so thinking we'd see it here makes little sense. Obviously Father Time is undefeated but there are outliers as to when that time comes. Merab looks like the Tom Brady of MMA, approaching the age where most guys fall off a cliff but looking like he's dead in the middle of his prime. Oh, and I played college football, had a (very brief-2 fights) MMA career etc and am in my 40's so trust me I know all about the effects of aging lol.
I know you aren't picking Yan to win, but if he does better this time I can't see it having to do with Merab slowing at all. It will be due to good adjustments from Yan, whatever those might be.