The spirits from my world require contracts to be made so I can use their power...so the ones sound easier to use...I haven't been taught to contact spirits yet though.

Just understanding them. There's two ways a Demon Lord can learn magic. Just learning its name, and how to use it is the easiest, learning the incantations are harder, but if I learn those, I can use the spell even when I'm in another demons relm. [Don't mind him sounding so proud of himself. He's happy he remembers all of this]