What? He simply was not an enormous wuss like everyone else in this series. He was no different from the average samurai anime character. I saw no behavior that would make me think he was more than human, like everyone else in this show is. A lot of people don't do so well in combat when they get a katana thrown at them. Nor when they get charged at and slashed. Guns don't do you very well if you panic, and they do even worse at close range. He had the advantage pretty much from the moment he got out of the car. Being soft toward his cowardly whore of a granddaughter was his only weakness. At least he gave her some wise parting words to ponder over. Gai will just throw her away like trash. She's a stupid, lovestruck girl who has let her hormones and pride override her intelligence.
Arisa the Whore is commendable for her actions in that scene at least. Sure she cowered in fear from her grandfather's slash, but at least she discharged her weapon properly while doing so.
By the way, have we ever seen that samurai/bodyguard woman that was with him earlier before? When they were talking about the Illuminati or the Da'at or whatever.