One thing I forgot to mention in my response to the ask about which scholar Siberian was: If he really was a big-name scholar like Garth or Rogers, that’s totally another point towards “great potential wasted on evil”. Though it’s worth noting that unlike Mannequin, the potential on this front wouldn’t be through his power.
Though there is the part I already had about how Siberian’s power might be able to harm or even kill Endbringers.