I have been thinking since I saw that the ancient plate set had a negative resist to sleep. Shouldn't they bring back slooms, sloombargo and these monsters;
Sleep Wisp
Typical wisp,except it deals sleep.
Drowsy polyp.
A polyp that inflicts sleep within its spikes.
Since OOO banned sleep, those sleep resistant trinkets are useless. This also gives us a chance to get possibly a sprite that deals sleep.
Sleep hasn't been fixed. Hence why slooms+Sleep UVs are removed.