>>11388066
Granted, you are now a genius loci, a kind of spirit tied to the land. Unlike normal genii locorum, however, you possess a mobile "spiritual core", roughly the size of a bus, that holds your consciousness and can move around. You can manipulate the land within a certain distance from your core, and perceive things that happen inside that range; this depends on distance, which means that you have less control over the land farther away from your core, and likewise your "land senses" will become less precise at long range. Your core normally is fused to the land, but as a workaround you can create a humanoid (womanly) body for yourself. Any attack directed at the land you control will damage your spiritual core, and it will get worse if the attack targeted the core directly. Keep in mind, however, that "attack" here requires specifically hostile intent, so if a construction crew just-so-happens to excavate your pussy without knowing that the ground is alive, you will not suffer any pain or injury.

Okay, that covers the "becoming a monstergirl" part, and you certainly have the resources to become a domme. But what about the part where you get the cute monstergirl subs? ...Well, have you ever heard of "random encounters" in RPGs? Where monsters appear out of nowhere to battle the heroes? Well, you can spawn your own subby monstergirls. Literally. As in "giving birth to them".
Part of you is pregnant pretty much all the time, spawning loyal monstergirls ready to serve you; but which ones you get is randomized, and depends on the location you're currently in. If you are in a forest, you might get things like wolf girls, elves or dryads. In swamps, you can get frog girls, lizardfolks, and slimes. Want to live in a city? You might get more vaguely "modern" stuff like robots, lightning elementals, and kasa-obake.