Line by Villain does look extremely nutted. But there's some chance that Villain is shoving something like AJ. Overall, I think folding is fine.

You say that bet/folding is better. Maybe it is. But couldn't you check/call river hoping for a value bet from Jx? You should be checking river sometimes and putting some full houses in your checking range is nice.

We have all the nutted boats here , more than SB should, AT,AK,AQ. This is our weakest boat I think folding is ok

I think we should bet really small on river to let trips or straight call. Obviously we dont need to call vs shove as we have plenty of better hands for that.

I don't think river is an easy fold but probably a fold. You have lots of better hands to call, AA, AK, AT, AQ, QQ. So TT is pretty low down in your range after betting 3streets, maybe you'll also have Ad2d-9d that you can comfortably fold.

What bluffs do you have on that river? Maybe KQ w/ Kd, or QTs (if you open this from utg)? You likely don't have too many bluffs so when villain jams I don't really expect him to try and fold you off an ace when the board runs out so amazing for UTGs range. It's likely AQ-AK and maybe if he's really sick turning weak aces with the fd A5dd into a bluff. (Although that blocks a lot of your folding range)

Also why do you think he's a reg if you only have 100 hands? Him flatting an utg open from the sb is not very reggy

Yearh, as weird as it is, with this board here we are at the bottom of our range and most people will not find a bluff here. we can call river with AQ, QQ and AA as well as AK . We have an insanely strong range here and villain should know that if he is a reg so it is a good trap spot on river for him with AT or AQ