Its shocking that they went with this type of scenario cause most authors would go with the "I wanna help and go back home" and then its the same old same old.
@Red225 not necessarily, if this manga follow MTG format to a T, then there exist card that can create unit without the card being "tapped" (in the manga term, only once a day) which i assume the elder is one. So he can make as many 1/1 elf token as long as he have the mana for it, and considering the elf tribe innate(?) ability is basically tapping creature for green mana, the MC can create soooooooooooooo many elf in just a couple of day basically overruning the world with elfs.