This plugin adds a new admin knife to the server called Banhammer. Banhammer deals insane damage on both primary and secondary hit (around 100,000), however the secondary attack also bans the player for X minutes and shows some explosion effects. This is like the best plugin ever.
Admins with the necessary flag (ADMIN_RCON by default) receive the knife automatically on their spawn. The knife is not droppable and it's possible to switch to a different knife using the R(reload) key.
Admins with the protection flag (ADMIN_IMMUNITY by default) cannot be attacked by the banhammer at all.