There are actually a number of different factions within the Jouishishi rebellion, some more extremist than others. Katsura's faction grew moderate as the anime progressed, from the the initial opening scene in Episode 5 where Katsura used terrorist-like tactics like time bombs liberally, to the Benizakura Chapter Episode 61 where he pleaded with Takasugi Shinsuke that there must be other ways of changing the world other than destroying it all. However, he was still happy to deploy bombs liberally against Shinsengumi.