i wrote a small extension with the help of o3-mini-high:

You can download the zip-file here: carnageblender-chrome.zip
Should work with any chrome based browser (e.g. chrome, opera).
Just unpack the zip somewhere and open 'unpacked extension' in your browsers addons manager.
.. might get slow once there are too many fights stored. You can clear the local db with the link.
Does not take bonus-xp into account, just fetches the xp per minion stat from the fight rewards. List becomes scrollable with enough opponents in there, shows last fight on top, highlights line with new average from last fight.
Use at your own risk and have fun :)