A Pantheon of Hallownest Speedrun in 14 minutes 56 seconds using glitches.

Glitch timestamps:
0:00 Extra Charms
2:17 Dreamgate Invincibility

Note: The beginning part is me showing how to equip extra charms. This process can be repeated as many times as you want and the charms are NOT reset upon reloading the game.
My full build was:
Steady Body, Nailmaster's Glory, Quick Slash, Fury of the Fallen, Flukenest, Strength, Shaman Stone, Soul Catcher, Spell Twister, Soul Eater, Dream Wielder, Sharp Shadow, Dashmaster, Wayward Compass, Gathering Swarm, and Stalwart Shell.

On another note, this was a latest patch speedrun. Making use of buggy nail arts on patch 1.5.68 would theoretically be faster.