Covered with Scars: Given how we're first introduced to Toyohisa and his near suicidal tendencies in fights, is it any wonder his body is riddled with battle scars? And after his bout with, Hijikata Toshizō, his growing collection shows no signs of slowing down.
Honor Before Reason: He'll show mercy to any enemy that discards their weapons and will never kill a girl. Unless they've done something like raping prisoners.
I Shall Taunt You: Olminu comments half-seriously that although he doesn't do it deliberately, Toyohisa is a genius at provoking his enemies into fits of rage and frustration; as, Joan of Arc, and Hijikata Toshizo, and even the Bigger Bad EASY found out the hard way.
Shut Up, Hannibal!!: How does Toyohisa deal with the trolling garbage spewing from Rasputin's mouth. Why he just kills his soldiers and beats the crap out of his political pawns in front of him. I think that would shut most evil manipulative bastards up. Not that Toyo was really listening in the first place.
Wouldn't Hit a Girl: Wouldn't kill one if he can help it, but he does kick Jeanne in the gut then knock her out with a headbutt when she refuses to surrender.
Arson, Murder, and Jaywalking: When trying to intimidate Olminu, he proclaims his villainy which includes arson, mass murder, making toasts with the skulls of men he has killed, taking over the country, and dancing "Atsumori".
Mythology Gag: He compares Saint Germi to a man who "made a bomb out of a tea kettle" - his old enemy Matsunaga Hisahide. He's promptly surprised when it turns out Saint Germi reveals he knows about Matsunaga, and refuses to be compared to him.
Badass Grandpa: When tested by Toyohisa to determine whether or not he would be an asset to them, and thus allowed to stay with the group, he stops the much younger, stronger, opponent dead in his tracks with a twig. Sure, it's used to emphasize a point with him, and he doesn't actually try to fight him (having gone senile and being obviously aged as he is), but that he was actually able to stumble Toyo with an object lesson and convince him he would be valuable to them definitely counts as an example of this trope.
Cloud Cuckoo Lander: Has definitely gone senile, that's for sure. However, he does have his moments of clarity, and when he does, it's usually wise to listen to him, even if he explanations are difficult to comprehend at first.
Good Powers, Bad People: His power is life itself. With him being capable of healing any wound, creating a endless supply of wood and organic supplies, and even capable of creating cancer in his enemies by making a excess of life.
Not So Stoic: Can't really blame him for losing his cool when he was faced with a ancestor of one of his most hated enemies responsible for the deaths a lot of Shinsegumi. That and unnerving enemies is a natural gift to Toyohisa.
Joan of Arc
A-Cup Angst: In the omakes where the Black King mocks her for it.