I read this novel some years ago. It's Korean Webnovel. The premis is, he got transported (of course), to other world. But each transport he got a mission to do. In one of the arc, he must guard an elf settlement and its World tree. And he got to play tag with the elves kids on top of the tree, kinda play tag with parkour. In remember he got a wind spirit power. And In his IRL, he saved some old CEO dude, the most powerful one, from health reasons. Ah, and his little sister friend tried flirting with him. And segs. When the friend know that he rich.