Just run susanoo in everything...
High strength sentries can be a pain for Kate to deal with though. Taurus in blue sun isn't bad, and can typically only be beaten by atman at 5. Susan in RP can be beaten by atman at 7, but thats expensive and they'd normally want it at 4. Ices like data raven and Gutenberg will be annoying if your deck can make them care about tags.
Also, tollbooth is good pretty much all the time, so it's good against Kate too. If they're on double CyCy, put a codegate on every server and the remote.
Just in general, doesn't RP have a fine matchup against Kate? I know on the rare days I decide to play RP, I'm much more afraid of seeing an anarch on the other side of the board.