Pacify
Because you hit the enemy enough, it got TIRED.
Now, if I use my PACIFY spell on it...
It'll fall asleep, and we'll win peacefully!Ralsei, Chapter 1
Pacify (JP: スリープ) is a spell in Deltarune, usable by Ralsei. It costs 16% TP to use in an encounter. If an enemy is TIRED, he can cast this spell to instantly SPARE them. If Pacify can be used and there is enough TP, Ralsei's MAGIC icon flickers white, and the spell's text flickers blue.
In Chapter 2, Noelle has a version of Pacify, called Sleep Mist (JP: スリープミスト). Sleep Mist costs 32% TP to use, but affects all enemies that are TIRED.
Starting in Chapter 5, Susie gains a version of Pacify, called Scythemare. Scythemare costs 40% TP to use, and is otherwise identical to Sleep Mist.
Starting in Chapter 2, when using Pacify, a swirl of "Z"s congregates around the targeted enemy. When using Sleep Mist, Noelle conjures swirling clouds on enemies. When using Scythemare, a spinning scythe, similar in appearance to Susie's axe (or Devilsknife, if equipped), appears overtop the enemies, alongside a "Z".
If Ralsei has the BlueShoes equipped, Pacify's TP cost will be reduced to 0.
Pacify becomes available as soon as Ralsei joins the party in Chapter 1.
Pacify is required to end the Jevil's fight peacefully after increasing his Tiredness meter to max.
After the battle against King, if an enemy was defeated by FIGHTing, Ralsei uses Pacify on him and puts him to sleep before he can attempt to kill Susie.
After defeating the first two Werewires encountered in the beginning of the Cyber World, more show up, before getting pacified by Ralsei. Ralsei claims that he has put them in "sleep mode".
Sleep Mist becomes available when Noelle is found in Cyber City and joins Kris as a party member. Sleep Mist becomes unavailable when she leaves the party.
Susie unlocks Scythemare at the beginning of Chapter 5, and can use it as early as against Trashy Trio.
After escaping Flower Castle's jail, several sleeping Floradinns can be found. According to one Floradinn, who is somehow able to speak clearly while asleep, Ralsei pacified them all offscreen.