In the first chapter, the MC isekais once and reincarnates twice. The title says he's an F-rank, but he retains his memories and abilities as both the world's strongest mage and the world's strongest swordsman from his previous two lives. The first chapter ends with the MC using his peerless sword skills to massacre a horde of goblins with a wooden stick. In the second chapter, he becomes a master monster tamer just by feeding a slime a piece of jerky. He's F-rank by choice, not because his ability is poor. When the MC starts out one step below the gods, there's not much further up you can climb.
The art is really low-effort. The backgrounds are generic and the artist seems to have some trouble with perspective. A lot of things look far too flat when the artist draws them at an off-angle.