Hey man,Obviously here, you got a cooler. I would not worry about it too much. Since he is 3-betting a lot, the chances that he is holding an Ace goes down (since he is going to 3-bet with a wide range of hands) so the chances that your king is good are very high in my opinion.Before I answer with the 3-bet though, I just want to let you know that I am still learning the game and that my reply is in no way accurate. It is just my opinion of what I think works well.When someone 3-bets me very aggressively, I reduce my opening raising range and I wider my 4-bet shove. I think this works quite well with most super agressive opponent.What you can do to vizualise it is this. Open pokerstove, enter the % of time you think the opponent 3-bet you (20%, 40%, 80% etc..). If you are like me, you are going to be surprised of how wide the range is. You are going to realise that a fair % of the time, you are ahead. Here with KT, I would have 4-bet shove. I would think that calling is also good (depending of how does he react after the flop). The problem I see with those people is they don't shot shot down after the flop. They 3-bet then they call/bet every street with crappy hands just because they want to see a showdown or bluff you out of the hands. So, when I don't hit anything, I am not sure what to do and I don't know where I am in the hand (even maniacs hit once in a while). What I am trying to say is that 4-betshove often solve that problem.Example: you have K9s and your opponent 3-bet you (he's been 3-betting you 50% of the time since the game has started). You can enter k9s in the first field and 50% of the deck in the second one. Then you are going to see your expected winning % if you shove and he calls.However, more importantly, if he 3-bets you a high % of the time, there is also a good chance that he is going to fold to your 4-bet shove a lot since most of the time, he is going to have no better then a marginal hand.I don't know if my reasoning is good but if it's not, I am sure someone more experience is going to correct me. 

I think your play is pretty standard.The only other valid play I think would be to fold to the 3-bet, but I'd be calling there.bonafontz, I think 4-bet shoving K10 would be very marginal. I don't think you can simply asign a percentage range so early, it may be a polarised range of junk and monsters, he could also be just getting dealt great hands. Also, you dont know his 4-bet calling range.For example (just a made up example not saying this is how he is actually playing), his 50% range may be top 25% of hands and the bottom 25% hands, that gives us 44% equity when called (about half the time) and folds  half of the time giving us negative equity (if my calculations are right.).K10 flops well so I'd rather see a flop.I think with stacks at 71BB (and a smallish 3-bet) you should only slightly widen your 4-bet range, the biggest adjustment should be widening your calling range. As stacks get shallower your 4-bet range can widen and calling range tighten. 

Good hand Monk.I like the comments about reducing (slightly reducing) your opening range and widening your 4bet range.However, I think that opening up your calling range and making sure you are minraising preflop on the button are the two most important adjustments against these guys when the blinds are 50-75bb deep.Calling with KT is really good here.  Further, you'll often call or bluff light, even when you missed the flop (against many aggros at least).  The key to beating aggressive players is not letting them run you over.  In order to accomplish that effectively, you need to make sure they aren't playing 70% of hands in a spot that you're only playing 15% (for example).  So you first make sure they aren't 3betting you out of every hand.  The second thing is to make sure they aren't pushing you off the flop with bets or raises.  If they are using very maniac like aggression in most hands, you can't just wait to hit a hand, you need to attack boards they are less likely to have hit, or boards they are more likely to believe you hit.  You also need to call lighter.  If a guy bets at every flop with a pot sized bet, why would you consider folding K hi even?  Those are the types of adjustments you want to make.In this hand, from my perspective, you played it perfectly aside from not minraising preflop.  Good 3bet call, perfect flop call as well as the turn (yes, draws get a cheaper card, but you're facing a reckless player, you can afford to flat instead of shove here when you have position) and of course river.  Standard, just a cooler, especially a cooler against somebody that 3bets a very wide range.

Perfect.Play, play play.  Review hands/videos.  Play, play play.  Repeat.