Ok so for maximum "ease" in the cosmic trial I'd recommend the following:
Team-Up: any Deadpool variant. The server lag graphic is annoying but it locks the Hulkbusters
Core: Invul on medkit, helps mitigate the DOT from Skull's dust of death if you get caught in it.
Medallion: Madam Hydra medallion for the DPS and invul proc is nice again as a breather.
Legendary: Warlock's Eye lv80, M'kraan lvl 70(if there's spirit issues), Gungnir lvl 70 otherwise.
The rest is just uniques (ilvl 66 is nice ilvl 69 is better), Decent artifacts with Hela's Blessings. A tanky insignia helps and the Cyclops insignia has a bunch of nice buffs.
Don't underestimate the value of Omegas. If you need some tanky nodes, Blob and Advanced Mandroid Armor are good choices (mandroid less so because your Emma isn't melee)
Damages nodes would be SPIN Tech, Xerogenesis, Warpath, Sabretooth, Psylocke (if you dash a lot), and Mind Over Matter. There's a ton of choices for damage but there's a couple basic ones.
I've managed to clear the Cosmic Trial with every hero using some variant of the above so I know it can be done. The catch is I have access to almost everything (Axis Raid uniques and the new boss artifacts are the exception) and 7500 Omega points to throw at my problems.
And don't worry about the 10k credits to upgrade a unique, that takes no time to replace and the boost is worth it if you put it on the best thing you've found so far.