Juggernaut is only vulnerable to magical attacks (and if the helmet is off psy attacks). 8th Day Juggernaut was a concentrated version of Juggeranut. He had a mission, so he used more power of the cytorrak gem (so thought). There was a comic where Juggernaut had a second helmet under the main helmet to help himself. I'm not sure Darkseid avatar's OE would do damage. If we go by Juggernaut's ablities then no (well it can teleport him) but no physical damage.
My question is why is Wolverine and Colossus there?