The subject of Day 18 is “Favorite Immortal / Outsider.”
This is going to be another hard one for me; I have rarely played at a level where extraplanar beings showed up much. So I’ll just pick one I think would be interesting to use in play.
Maybe Efreet? They are both “Outsider” and “Elemental” but Elemental / Plant monster gets its own day tomorrow.
An Efreet is basically an evil genie from the Plane of Fire. They are powerful, and can be summoned and made to serve for 101 day. However their Chaotic nature causes them to “creatively interpret” their orders when they can get away with it.
Although they do not grant “Wishes” like Djinn, Efreet must be treated with the same degree of caution as when wording a wish. Think long and hard about EXACTLY what you will order an Efreet to do, and the words you will use to do so.
For instance, imagine a situation where some city guards are fighting invading soldiers. Order the Efreet to slay the invading soldiers, and he may turn into a pillar of fire and roast both the soldiers and the city guards.
Once the 101 days of service are over the Efreet will depart, but you better pray you never encounter that exact Efreet again!