Linrim
A strange choice of worlds. They are no different in terms of resources and materials compared to the current one and the worlds of One Piece. Although if you look from the point of view of biology (zombies and titans), then the world of Star Craft is preferable to me (Queen of Blades and her Swarm ;)). Well, since our MC loves magocraft, why not the world of Arifueta? :) There is also a bunch of unusual ores and minerals, plus unusual magic for completing dungeons. Therefore, a partner can be picked up from anyone from the world of HP and from the world of Arifueta. For my partner and/or love interest, I personally vote for Luna Lovegood ;) at least for very non-standard thinking, plus she kind of loves to travel and animals. Alex will provide the trip, and he himself is still an animal :)