I don’t think this is as widespread as Lunatic Inquisition, and it may be a hack, not a bug, but I saw a Guardian today in Snowball Madness who had all of his skills, and was abusing Reatreat! and Save Yourselves! for swiftness and Aegis in the activity.
I reported the player (for “scamming,” because two years into launch there’s still no option for reporting hacking or bug abuse.) But it lead to complete domination by his teams because they always got the gifts first and needed 2 hits to be stopped.