Incineration of Humanity, the bleaching of humanity, the Seven Beasts, the Seven Grand Servants, the Fantasy Tree...
There's no mistake: this is the Nasuverse.
Ryan transmigrated to the Sixth Singularity, the Sacred Round Table Domain, and his only goal is to survive.
"When facing danger, stay calm instead of getting angry. If anger were useful, there wouldn't be any failures in the world."
Defeating demons, beating the Beasts, making Rhongomyniad abandon the Holy Selection, letting Salter continue to exist, allowing the banished Tiamat to live a normal life, and preserving the Lostbelts that were supposed to disappear...
Ryan only wants to survive in this dangerous world, but without realizing it, he has become a great hero praised by everyone.
"I never wanted to be a hero!" Ryan said helplessly.