The Medallion is too slow to drain XP, took quite a while to drain 33 levels of XP, it would be better if the more levels you have the faster it drains and get slower as the level drop

After draining all the XP you becomes Unable to get any kind of XP from any mean(even /xp didn't worked) that's why if you right click on the Hero's Medalion after draining you loss all the XP inside of it, using the Hero's Medalion after dying seems to work so the problem is after the draining

This is fixed in the latest build.

I'm still looking at this one. The reason for it breaking is it seems to slip every so slightly into the negative and I don't see why. It should be stopping at 0 based on the formula, but it fails to do so.