Tide spirit
Tide spirit is a great elemental of water. When a mage of Reverie casts Summon storm spirits and reaches into the Welter, this is one of the shapes that can rise. It comes as a moving wall of dark water.
It strikes from afar, drowning and choking what it reaches, and it lasts a long time in battle. Blades pass through it as through a wave. Mana keeps its shape, and its upkeep, paid in mana alone, is heavy. Withdraw the mana and the water falls and is gone.
Aefenna, the Lamplighter holds back night without ending, so that power may ebb and return. Each return brings every kingdom a turn. Reverie cultivators say the tides of the Hallow keep the same time: they rise and fall with the god's breath, and a tide spirit is that motion given a body. Mages who call one say it is restless between turns, as if it can feel the next one coming.