Tobirama mid-diff.
People are looking at this the wrong way, what they should be asking is, what can Sasuke do to hit Tobirama?
He's a very acute sensor with the ability to teleport and has the joint fastest reaction times in the series, and has fought Uchiha countless times, as shown when he recognised Enton and clearly knows about Susano'o.
Amaterasu takes time to build up the chakra, Susano'o's attacks are too slow and that leaves H2H (CQC is incorrect), of which Tobirama is proficient in enough to hold his own against SM RG Madz for a brief period, so MS Sasuke shouldn't be too problematic.
And for the finale, you may as well throw in the fact that Madara put Tobirama's overall ability in the same league as Hashirama (although he's clearly not level with him), the latter defeating EMS Madara.