Boon of Planar Binding Command

As an action, you can choose one creature you can see within range that is not native to the plane of existence you are on. The creature must succeed on a Charisma saving throw or be subjected to one of the following effects (your choice):

1. Command: The creature must follow a simple command from you, such as "flee", "halt", or "drop". The command must be no more than one word and doesn't harm the creature. The effect lasts for 1 round.

2. Banishment: If the creature fails its saving throw, it is banished to its home plane of existence. If the creature is native to a different plane than the one you're on, it disappears, returning to its home plane. If the creature is native to the plane you're on, the spell has no effect.

The DC for this saving throw equals 8 + your proficiency bonus + your spellcasting ability modifier (or another appropriate ability modifier if you're not a spellcaster).

Usage Limitation: Once you use this ability, you can't use it again until you finish a long rest.

Special Notes:

• This ability does not work on creatures that are immune to being charmed.
• The control is not absolute; the creature will try to follow the command to the best of its ability, but actions that go directly against its nature or self-preservation might allow it another saving throw.
• For creatures with a Challenge Rating (CR) much higher than your level, the Dungeon Master might grant them advantage on their saving throw, or for lesser creatures, they might have disadvantage.

DM's discretion: The Dungeon Master may decide that certain powerful creatures, such as deities or demon princes, are immune to this effect or have a different mechanic for resisting it, such as a Legendary Resistance.

This is a broad and flexible ability, and the DM might need to adjust the mechanics to fit their campaign's power level and narrative.