Fastest way to Bomb the Ender Dragon

Reaching the End is only half the battle in a Minecraft speedrun. While casual players spend twenty minutes shooting obsidian towers, professional runners use a mechanics-exploding trick known as "one-cycling." By exploiting how explosive entities behave in the End dimension, you can kill the Ender Dragon the very first time she perches at the central fountain.
The strategy requires immaculate timing and a hotbar stocked with at least 5 to 6 Beds, a few solid blocks, and Obsidian. When the Dragon begins her descent to perch above the bedrock portal, she becomes immune to standard projectile damage but remains completely vulnerable to explosions. Because beds explode violently when a player attempts to sleep in a dimension other than the Overworld, they serve as your ultimate weapon.
Place an obsidian block exactly on the top rim of the bedrock fountain, with a bed resting on it so the pillow faces the dragon's head. Stand underneath the ledge to shelter yourself from the blast, and right-click the pillow the exact frame her head clips into the bed. If timed perfectly, the explosion inflicts devastating continuous headshot damage, completely melting her health bar before she can fly away.