Summon Spirit Bear creates new bear whenever re-stolen and used by Rubick
Summon Spirit Bear is supposed to "recycle" the same bear, so that the hero has one bear per match, which gets revived whenever recast. However, when used by Rubick, it creates a new bear instead. Whenever he loses the spell, re-steals it and casts it, an entirely new bear is created, instead of the bear from a previous cast being used. Since the bears do not disappear after death like how other summoned units do, this can cause performance issues, the dead unused bears are still there, taking performance. It also causes unit group hotkey issues for Rubick.
The same issue is present with Tempest Double
, which works in the same way as the Summon Spirit Bear does.