Issue #2, The Battle Amongst the Flames in the hospital. Kaine doesn't hold back, even if it means grabbing a gun and unloading into the bad guy.
Issue #4, Kaine, after being on the run from the Assassin's Guild, cuts the leg off one, punched through another's head, tripped up the Tyke Bomb, and crushed the fingers of the one who could teleport and used guns, before calling up their boss and telling her she gets one job done and then leaves him alone or he'd kill everyone there.
Issue #17, Hummingbird (Aracely) managing to Mind Rape every single Psychic X-men in the Jean Grey School before Wolverine and Kaine try and kill each other, culminating in Kaine putting a stinger in Wolverine's heart.
Issue #18: Wolverine and Kaine vs tons of Assassins, whom they assassinate in droves and a multitude of ways.
Issue 19: Kaine and Wolverine vs the godlike Chandra, the Red Death and the terrified Assasins Guild.
Kaine: Well, I can't damn myself any more... Might as well kill a god.
Kane curb-stomping Kraven the Hunter. Truly majestic.