Bullshit, characters like Azathoth can simply blink him out of existence since everything is part of his dream meaning that if he wakes up, everyone and everything dies.
You're forced to fight:; No one; A spider; A scorpion; Georges St. Pierre; Alex Pereira; Jon Jones; Prime Mike Tyson; Tanjiro; Captain America; Batman; Iron Man; Spiderman; Ryu Hayabusa; Omni Man; Ichigo; Saitama; Goku; Doom Slayer; Kratos; Dante Sparda; Wonder Woman; Hulk; Anti Spiral; Dovahkiin; Thanos; Darkseid; Superman; Doomsday; Dark Phoenix; Unwritten Leviathan; The Presence; The One Above All; Azathoth; SCP-3812; Yog Sothoth; God