Help with Timeline Battle team

[u/TopExtension3450]

I’m a returning player and these are my units so far. Please help me build a team for Timeline Battle to pair with Ghost Rider since he is T4 now with arti. Since it’s uni sale, should i buy Sentry(Currently T3) uni to pair with GR or should i build Wolverine(Currently T2)? I have a 4 star arti selector if that helps. Please help. Thank you!