I can't really figure out very many made hands that would justify his line.
QdJd, KT and maybe 1-2 combos of 55? As far as KT combos go, how often do you think he flats KTo and how often he would 3-bet KTs? Also an important question, do you think he's capable of leading a merged range (AJ/55) on the turn? I assume that most 10/20 players don't lead AJ with these stacks on this board.

I would bet small to induce, like 180-220, and call almost every raise. This is why I think small bet/call dominates overbet here. I can't think of many hands he's bluffcatching with if you bet bigger, so it's better to induce. However, a veeeeery unlikely scenario, he could potentially valuecut himself with AJ and check-raise your small bet (although I would expect him to bet AJ instead of going for check-call).

Small bet is probably best from theory perspective too, because your valuerange is most likely capped at sets and you still have a lot of missed draws on the river (a long with weak-showdown hands you probably check back with).

I'd c-bet bigger than 2/3 3-way on a dynamic board like this. About 90-100 here.
Probably calling turn here. Villian could flat the SB with KTs and KTo (read?), and c/c with someone behind, but it's not his most likely line.
But you're not going to raise much on this turn with your range, so keeping a hand like this in is nice.
If you have Qx/Jx + gutshot, you'd call. If you had Ax or a FD, you'd call.

On the river, I'd just go for a regular 75% bet. This is not a board where you'll be super polarized, and neither player is capped, so I don't like an overbet.
Betting small allows him to call with more bluff catchers, but I asssume most of them are Ax, which 3-bet pre. Don't think a hand like QT calls here.

i would assume his turn leading range is very polarized until shown otherwise, making a smaller riv bet or checking much better w/ the majority of your range, i think overbet here w/ anything is v bad.

I'd definitely bet this river. Any size will do, depends on how we play our range in this spot + how we play in general and might be viewed (not so relevant here with anonymous table, so all of that is not such a big concern, and you can go with the size you feel is best for the situation).

I think we have a lot of incentives to bet big as we get to this river with many hands that will want to bluff.

A small bet is good if we have a very solid and value-oriented style of play, as we'll float less and bluff less in general. As vilain has probably no real reads on you, I'd discount that he has this image of you, so I'll bet big. Also, I'm not convinced that a small bet will induce more bluffs, it might be the opposite actually.

Like, I just don't see point of betting >50% pot if OP's statement is true:

"I wouldn't expect him to have much of a  x/c range here, he may even x/r more than x/c."

If his x/c range here is very small, what's the reason for betting big? We price him out from bluffcatching with weak hands, discourage him from bluffraising and price ourselves out from calling.

If this guy is a reasonable player, I think the type of range we should expect from him the stuff that makes the most sense to me in order of likelihood would be diamonds/QJ/JJ > KT > AJ

QJ stands to lose the most the times you check back the turn w/ your marginal aces that would always call a bet.  KT also might miss a checkraise for the same reason, but KT doesn't block you from having any potential two pairs or sets so I think that can be discounted a bit.  I put these broadway combos in his range often because of stack depth.

So when he has diamonds he's always folding.  When he has worse 2pr/JJ he's always calling and when he has KT he's c/shoving.

I think 3/4 psb is the correct bet here.  Also, I'd just call turn w/ KT in your spot as well so I have no problem bet/folding here since my range is protected.

To your point Peter, Readless, I'd expect his AJ or even QJ to lead river some percentage of the time. I don't think it would be in my stratedy to lead turn and check river with those holdings. 

I think it would be pretty cool to play your Txdd and Kxdd as a CRAI on the river to balance the times you'd want to do it with KT. If i had missed diamonds i wouldn't expect to get enough folds by betting again on the river. 

You say your range is protected against a X/R on the river because you can show up w/ KT so you can b/f all your non straight hands. But if his stratedy is to bet AJ, QJ on the river himself, X/R KT, and draws, and x/f the rest i'm not so sure this is true.

Ya I agree all those should pretty much just bet river themselves.  But I stipulated everything I said with 'if he's a reasonable player' because we have no idea really.  If he's not, we should still just do a normal bet here.  People just don't really take this line as a bluff because it's kinda suicidal against the average player pool which generally doesn't like to fold much.

Results?