Go to the Paimon menu > go to Buy and go to the Character Outfits section to find the Outfit, which you can buy for 2480 Genesis Crystals.
On the occasion of the version 2.8 Summer Fantasia update that will be in effect until August 24, 2022, the skin will have a discount of 1980 Genesis crystals.
To get crystals, you will have to go to the Crystal Top-Up section of the store, where you can buy them using real life money.
This is everything you need to know about how to get Red Dead of Night skin in Genshin Impact, so now that we're done, we hope we've been as helpful as possible, so you can get this skin as soon as possible.