First of all, I'm not sure why you would ask for ModrenSonic's assistance in the matter considering the fact that he wasn't the one who banned him. Next time ask the one who banned him (which in the case would be PKMNthehedgehog2.5 or GraveEclipse567).
Second, the issue has been resolved. PKMN messaged you providing you the reason for Ixisnagus112's ban which was sockpuppetry. Thanks.
I didn't know exactly who banned him. His userpage didn't say he was banned which confused me a little, so I figured this was more of a Chatroom problem which is why I asked for Modren since he's a chatmod.