Hello, ran into the memory problem again.
Playing as the wizard, had the double experience ability, faster orbs on level perk and proc ability on level perk.
When there are a lot of experience points on screen and you just got a burst of experience and you level up, there's a chance of you doubling the incoming experience points, which causes you to level up, which can trigger you doubling the onscreen experience again, which causes you to level up...
This loop also grows exponentially as each level up requirement seems to grow linearly (if at all) whilst the experience comes in multiplicatively.