Ah... so I worked out where this bug is... I've lost 500 points of speed (-491) and my ability to cast Fissure is locked, which implies that it's been bounced somehow, locked itself to me, and it can't work out how to detach the debuff now because the duration was applied to the enemy, rather than me?
There seems to be a dead patch while your power is in the quintillion/sextillion range - I note there are no upgrades between quintillion and septillion...
that is intentional to slow down the soul gaining a bit :)