This is Mega Man Classic versus the newest Terminator model (as of Terminator: Dark Fate).
Only primary canon for Mega Man.
Round I) Mega Man vs. the REV-9. No Robot Master Weapons, but gets the Double Gear System.
Round II) Mega Man does not get the Double Gear system, but he will have his Special Weapons from Mega Man 11.
Bonus: Gemini Man (DWN-019) takes on the REV-9.