Erdan's Summon Greater Celestial

You utter a beautiful song, summoning one celestial from the upper planes of Elysium. You choose the celestials’s type, which must be one of challenge rating 5 or lower, such as a Couatl or a Unicorn. The celestial appears in an unoccupied space you can see within range, and the celestial disappears when it drops to 0 hit points or when the spell ends.

Roll initiative for the celestial, which has its own turns. When you summon it and on each of your turns thereafter, you can issue a verbal command to it (requiring no action on your part), telling it what it must do on its next turn. If you issue no command, it spends its turn attacking any creature within reach that has attacked it.

At the end of each of the celestial’s turns, it makes a Charisma saving throw. The celestial doesn't need to make the Charisma saving throw if you speak its true name. On a failed save, the celestial goes back to Elysium. On a successful save,  the celestial stays until the next turn when the celestial makes another save. If you stop concentrating on the spell before it reaches its full duration, an uncontrolled celestial doesn’t disappear for 1d6 rounds if it still has hit points.

As part of casting the spell, you can form a circle on the ground with the water used as a material component. The circle is large enough to encompass your space. While the spell lasts, the summoned celestial can’t cross the circle or harm it, and it can’t target anyone within it, you can also consecrate the ground with the water doing this will let the celestial automatically succed its saving throw. Using the material component in this manner consumes it when the spell ends.

At Higher Levels. When you cast this spell using a spell slot of 5th level or higher, the challenge rating increases by 1 for each slot level above 4th.