Played Magtheridon using Demon Hunter in Arena which I discovered using Jumpscare spell. When I summoned Magtheridon the " Summon 2/2 Copy of this " Effect , did not work and only my original Magtheridon was summoned and went dormant. I think the issue is with dormant minions , 2/2 copy effect does not work to summon dormants , its still a minion so this effect should work as stated.