This cape smells faintly of brimstone. While wearing it, you can use it to cast Dimension Door as a Magic action. This property can’t be used again until the next dawn.
When you teleport with that spell, you leave behind a cloud of smoke. The space you left is Lightly Obscured by that smoke until the end of your next turn.
RollQuest ships the D&D 2024 SRD as a content pack, on a 5e character sheet that does the maths - roll from the sheet and let the numbers work themselves out. Free to start.