Tempest-Tossed Spells

Note: This feature is intended for use with the Background Tempest-Tossed, itself intended solely for use with a specific subclass: Doomed Wild Mage. It's part of a set of character options that only fully make sense when used together.

You learn an extra spell at the following levels; spells learned in this way are always prepared. Once per Long Rest, you can cast a spell learned this way without using a spell slot.
9-Banishment
11-Contact Other Plane
13-Arcane Gate
15-Etherealness, Plane Shift
17-Demiplane
19-Gate or Astral Projection