Hot Air Balloon

Well if you were close enough to spawn, they kill monsters and respawn them immediately on death so you actually were able to kill multiple monsters with 1 doppelganger, regenerate the deaths, and get stars at the same time. So I'm personally glad they disabled it.

Wait wait wait, how do you kill more than two monsters with just one use of Doppelganger?

“	respawn them immediately on death	„

Oh right, the clones still keep attacking. I never really noticed Doppelganger giving me multiple sets of stars...

You have to be near their spawn or they'll die then respawn way too far out of range.