Fire Breath (Recharge 5-6). Dexterity Saving Throw: DC 13, each creature in a 15-foot Cone. Failure: 22 (4d10) Fire damage. Success: Half damage.
Weakening Breath. Strength Saving Throw: DC 13, each creature that isn't currently affected by this breath in a 15-foot Cone. Failure: The target has Disadvantage on Strength-based D20 Tests and subtracts 2 (1d4) from its damage rolls. It repeats the save at the end of each of its turns, ending the effect on itself on a success. After 1 minute, it succeeds automatically.
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.