Slash (Unarmed) is a boss in Chrono Trigger that appears in Magus' Castle in 600 AD. A very easy way to defeat him is to equip Frog and Crono with Berserker Rings, and simply go all out while Robo uses Robo Tackle. This strategy works very well, so well, in fact, that the player may not even need to heal by the end of the second battle.