Minecraft wiki entry for Player_versus_Player, associated text: For maximum damage and a near-foolproof way to kill, wait for any enemy juggernauts near the vicinity to jump (either to critically hit you or because they couldn't hit you without standing on one of the obsidian blocks and attacking below) then place and detonate 2-3 crystals in quick succession. This is because a player's feet is much more susceptible to explosion damage, and even if someone uses an enchanted golden apple with full blast Protection 4, three point-blank end crystals would still be a guaranteed death. You'll take some recoil damage from this, but as long as your feet are below the crystals, the amount you take is minuscule to the amount you & your juggernauts dish out, buying your allies time to retreat and wasting the enemies far more resources, sometimes even forcing them to retreat as well.