If you're taking Danzo at his peak, then his arm isn't sealed. That's a restriction he places on himself in some fights, but not in others. Nor does it require any special prep, etc. It's not unlike Inigo fighting left handed to test himself. You shouldn't assume bloodlusted Inigo is fighting left handed, you take Indigo at his best (provided that best is consistent). Unless the OP specifies no Izanagi, then he's got it. He's also got the Sharingan to predict movement, etc, so that should let him dodge until he un-seals it anyway. Neither has any answer to Izanagi, so Danzo stomps. Indeed, if it's no special knowledge in advance, they won't even know what is going on, and will be stunned that Danzo has a sharingan.
