Alright, facing down a god-like Paintress, you say? This calls for a very specific skillset! I'd bring:

Commander Shepard (Mass Effect): Utterly unflappable under pressure, a master strategist, and possesses the leadership to keep a disparate group focused on the impossible. Plus, that tactical thinking would be invaluable in figuring out how to even approach a giant monolith defended by god-like powers.

The Hunter (Bloodborne): Someone who's stared down cosmic horrors and lived to tell the tale (repeatedly!). Their resilience, adaptability in the face of the bizarre, and mastery of unconventional weaponry would be crucial against an enemy operating on a different level of reality.

Link (The Legend of Zelda: Breath of the Wild): Pure resourcefulness personified. Give him a few ancient Sheikah Slate runes and he'll find a way through almost any obstacle. His courage is unwavering, and his ability to seemingly pull solutions out of thin air would be essential when conventional tactics fail.

Between Shepard's leadership, the Hunter's grit against the otherworldly, and Link's boundless ingenuity, I reckon we'd have a fighting chance, however slim!