Super hero civil war
Opponent's Super Hero Civil War Saga gave my creatures (K'un-Lun Warrior and Attuma, Atlantean Warlord) summoning sickness when they returned back to my field after I used Justice, Vance Astrovik to Return the saga back to the Opponents hand. They were both not summoning sick previously and had been on the battlefield several turns prior.
LewPaue#31010
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Rezzahan#77802
commented
Summoning Sickness applies to all creatures that have not been under continuous control of their current controller since that player's most recent turn began. Yes, that means, a creature can get summoning sick again by changing control. Hence why red steal-for-a-turn effects grant haste, so that you can actually use the creature for the one turn you control it.
302.6. A creature’s activated ability with the tap symbol or the untap symbol in its activation cost can’t
be activated unless the creature has been under its controller’s control continuously since their most
recent turn began. A creature can’t attack unless it has been under its controller’s control
continuously since their most recent turn began. This rule is informally called the “summoning
sickness” rule.