Although Theodorix's Magma is not the best Incantation in Elden Ring, it can be a great choice if you want something for effective AOE attacks. The dragon's powerful breath, spewing lava projectiles, can set a large area in front of the user on magma, causing damage both at the moment of the spell's eruption and upon subsequent contact with the lava. Of course, the FP and Stamina costs are relatively high, and you can't use it while jumping, but the massive damage looks quite attractive.