Not that they'd need this tactic, but with CIS off and it being a fight to the death, what's to stop Flash from boosting everybody's speed so they'd be too fast for the X-Men to even see, and Orion using his Mother Box to give everybody one of those swords Superman had during HUNTER/PREY that could cut Doomsday?
The only real problem I'm seeing for the JLA here is Colossonaught, as he might be hard to kill, if killing everybody on the other team is the victory requirement.
But even that, between a Mother Box and a Power Ring they could probably find some way to kill him.
__________________ Bluewaterrider: "I'm surprised that a Skyfather like Zeus defeated Hulk when Zeus' Top-Tier son Hercules has lost to Hulk."
Oh I have no doubt that with CIS off the team will have no problem whatsoever incapacitating Piotr. They've got multiple members with super speed, so yep, your scenario of removing his helmet then mind-rape him works perfectly.
BUT, if they have to actually kill every member of the other team, that could make things more difficult. With a Power Ring and Mother Box though, I guess they could scan him to figure some way to kill him. Maybe J'Onn can use his telepathy to make Piotr think his heart is stopping, and making it stop as a response?
I dunno, I just see that if the other team's death is the victory requirement, that makes this a bit tougher for the JLA.
All you need is Martian Manhunter, he is the perfect Anti-Juggernaut character.
Ability to not get hit, Telepathy, and the powers need to remove his helmet = a Juggernaut being owned by him.
as for killing him. Who knows I'm sure Wonder Woman's magical weapons could effect him considering at certain points in his history magic has shown to be able to by pass his enchantments at times.
So maybe her sword would work and she would be able to cut of his head.
Of course Cain has existed as just a skeleton with no nervous system or internal organs including a brain so who knows if decapitating him would actually kill him.
Also who knows if those examples pertain to Piotr as well as we don't know for sure if he is using the full powers yet..