I was talking about several of the vestiges. Then again you might have been one of the vanus' that got settled with a decent vestige. With as many necromantic vestiges I could see I figured the chance was high enough to just ask. I do still wonder how the other vanus' managed. I hope they are well.
Several Vestiges? Other Vanuses?
Are you implying that you have knowledge of alternate timelines? Perhaps even access to them? Such magic is a highly volatile and extremely dangerous art, and if what you are saying is true, I must advise against using such power without the proper understanding of what meddling with time can do.
This said... I suppose, to hypothetically answer your question, though I cannot speak for... alternate versions of myself, I know that such a situation would be... difficult for me. As you have already mentioned, my stance on necromancy is very clear, and these beliefs will not waver.
Given the circumstances of the Planemeld, and what outcome would befall the entirety of Tamriel should it come to fruition... I would have no choice but to work alongside the Vestige, as they are a key part in the defeat of Molag Bal. Necromancer or not.
I can only imagine it being a rather, ah, unfavorable experience, being forced to witness countless necromantic feats in such close proximity to my person, with the knowledge that I can do nothing to stop it. Far too many memories spring to mind. Horrible, awful memories.
...I do hope those versions of me have managed to cope, as well.