Asphyxiate

Reaching out into the area around you, you create a void around a creature's head, making it impossible for them to breath.

When you cast this spell, choose a creature you can see within range. This creature must make a Constitution saving throw. On a failure, this creature begins to suffocate, and can only hold its breath for a number of rounds equal to it's Constitution modifier (minimum 1). After this time has elapsed, the creature must make a DC 15 Constitution saving throw at the start of its turn or fall unconscious. If the creature succeeds, it must continue to make the saving throw at the start of each its turns for the duration of the spell, the DC increasing by by 5 for each round it has attempted this saving throw. If a creature succeeds this saving throw twice, the spell ends. Creatures who do not need to breathe are unaffected by this spell.

At Higher Levels. If you cast this spell using a spell slot of 2nd or higher, you can target on additional creature for each slot level above 1st.