Mousasi would be a handful even for a younger Vitor. Excellent chin, good grappling, technician standing.
I don't think older, battle worn Vitor has much of a chance. Tough stylistic matchup for Vitor anyway.
WTF is this technition standing bullshit you guys are always claiming about Mousasi? His striking is average as fuck. He has a good jab, and that's about it. He has good defense as well. Other than that, he has never been a KO artist and he strikes very lazy without a lot of explosiveness in his combos.
He is nowhere near Vitor's level of striking.