You also need a certain level of stats in order to wield certain weapons. One-handed weapons/shields that have a high strength requirement that you lack can be clumsily wielded by holding it with two hands, but I don't think that works for Dexterity.

Eventually, certain weapons will become much more powerful depending on what stats you have built up. My weapons in the game all revolve around my Magic stat and deal Magic damage, which many enemies are vulnerable to.

You can kind of arrange multiplayer if you have a way to communicate outside of the game. Basically, you say 'meet me at this place, and I'll drop a stone to summon you'. One of you (the summoner) has to be alive, and the other one must be a spirit in order for you to meet up.