A long time ago in the early 2000s, the original development team at GRAVITY created an RPG known as Arcturus: The Curse and Loss of Divinity.

YouTube Video
YouTube Playthrough

This game became the basis of what players know as Ragnarök Online. The original developers even implemented NPCs from Arcturus into RO as Easter eggs for players to find. Unfortunately, Arcturus was only released in Korea and Japan so the references are lost on non-Korean and non-Japanese players.

Then the original development team left GRAVITY and formed what is now IMC Games. It's much more pronounced that Tree of Savior is a spiritual successor to Arcturus than RO.

Just call me The Gardener.