You gain one of the following feature options of your choice. Whenever you finish a Short or Long Rest, you can replace the chosen option with the other one.
Escape the Horde. Opportunity Attacks have Disadvantage against you.
Multiattack Defense. When a creature hits you with an attack roll, that creature has Disadvantage on all other attack rolls against you this 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.