$400k guaranteed at Venetian. Multiple starting days and prize pool more than doubled to $800k!

We're 2-3 levels from bagging for Day2 and I'm sitting on 74k at BB 2k (37bbs) after having just run it up from 9bbs. My image was tight having arrived at this table with 20bbs and grinding down, getting some shoves through, and finally doubling up a few times and gaining momentum. The table was mostly tough aggressive grinders. Stack sizes ranged from 60- 200k.

Villain opens in UTG +1 to 5k from about 100k stack. He has been way out of line with his opens. More on that later.
Folds to hero on button and I 3-bet to 12k with AJo
Folds back to Villain and he flats. Heads up to flop.

J 7 7 - rainbow

Villain checks
Hero bets 15k
Villain shoves and covers.
Hero?

Thoughts on all decision points appreciated. Mostly the flop here after he jams. Are we folding near the top of our range of here? I feel like my image is so tight that my range looks like AJ, QQ, KK, AA so this looks like a value shove from him. Value hands = 67s, 78s, 97s, maybe even worse like 107s. Does he do this with value hands like 10J-KJ, 99 even? He will likely just flat these hands I would think but he is a crazy player so who knows. Bluffs= not finding many but it's possible with 89s, 109s,108s.

He is a mid 20's asian player with a very LAG image. He had been opening nearly any two cards. At one point he opened 94s utg and called off short stack's shove. I had also seen him check raise with air in a BvB pot. More on my image- white male about 30 yrs old, backwards hat, backpack, standard tourney grinder look I suppose.

Thanks!