Guillotine-of-short-back-and-sides

Scalpel

Yarmulke of ????? (the diplomacy one)

Yarmulke of sack-cloth-and-ashes-for-the-humbly-penitent

Yarmulke of painful-but-nonetheless-spiritually-beneficial-minor-surgery

Yarmulke of elimination-for-stubborn-to-remove-protrusions-of-pride