2/5 NL, 6th hour on the table. Hero has about $900, Villian has about $1200. Villain has been raising to 30-35$ preflop a lot, has rolled over everything from 87s to AJo and above in those situations. He has been calling raises after limping probably about 75% of the time. He is on second buy in after a seat change, so is probably about even on the day.
The hand:
Villian (UTG) limps for 5$. One more limper. Hero raises to $25 on cutoff with A

K

. Button (very loose and running very bad) calls. BB calls, Villain calls. Four to the flop.
Flop comes A

6

2
Villain checks, hero bets $100. Button and BB fold. Villain raises to $250.
The question is what is our play here? Are we ever against AK/AQ/AJ on this and villain thinks my preflop raise was position and i cbet the flop? Are we against A6 or A2s? Is a set ever raising on the flop when its heads up at that point? I'm most interested in what range folks put him on, and who would get away from this hand on the flop and why?