Occasionally after defeating a wave, and while waiting for other players to finish, summoned units will get caught in a loop, running upwards, before being teleported to the bottom of the lane (not the catch area!). This will repeat until all other lanes are resolved, at which point the imps disappear. However, this time the Imps spawned by Hades were running from bottom to top in continuous loop WHILE I was in build mode. They pathed around my buildings, until I blocked them off, and they ran forward to fight the enemy when the wave spawned (but ran out of health basically as they reached the enemy). This could be exploited to allow extra imps/summons to persist from previous waves. My friend (playing on a computer beside me) could also see them running around - it was not a local/client issue. I don't know how to replicate the issue - but hopefully the screenshot and logs help. I also submitted an in-game -bug report. UPDATE: I replicated this issue first try by creating a line of summoners in practice mode and typing "-clear" just as they started spawning units. I made it work several times with Imps, and once with a dragon. I can confirm the units DO fight properly, allowing this to give an unfair advantage very occasionally.