I don't know what broke or went wrong but once you identify that I would be very tempted to bend it back using a fulcrum of soft/padded material over something hard. We used to use boat covers over a picnic table and had great success straightening bent aluminum spars with 505s. Not ideal but we straightened spars bent worse than this one and I use to race one of the straightened masts in San Francisco Bay afterwards with no issues. I have done the same on other boats as well.

Sorry for the basic questions, but did you have the mast rotated all the way out while sailing with the kite? Was the main on tight enough? The bend is to the side which leads me to think the mast was not correctly aligned to the forces it was experiencing. Generally you would want the mast to be rotated all of the way out so that the stronger part of the mast (the fore and aft direction) is now working to support the side loads of the kite, main, and trapeze.

I am assuming it bent to leeward and that you were sailing on port? If so, it looks like it bend the only way it could - right in the middle of the unsupported area between the hounds and the spreaders. You are lucky it didn't break and now have a chance to fix it.

Perhaps the original sets of spreaders would have allowed the mast to take more of a side to side load.