Originally posted by JakeTheBank
X-Men.Thor by himself was able to channel the storm's fury in a blast capable of destroying a single secondary adamantium Ultron. Storm isn't Thor (obviously), but her and the rest of her teammates can come close to, if not meet that damage output by Thor.
He was trashed the Avengers for several minutes before Thor managed to take him though.
There have also been primary adamantium versions of ultron... An the only way they were able to defeat that ultron was by getting their hands on vibranium.
Secondary is not as durable as primary...
And kitty has problems phasing through dense materials... Such as adamantium... However as a suicide mission she could phase into ultron which would disable that gizmo inside ultron that allows him to move etc..
Other than that one an only option... Ultron wins IMO....