Action: you emanate an aura of sunlight. For 1 minute, bright light shines from you in a 30-ft radius and dim light shines 30 ft beyond that. Whenever an enemy creature starts its turn in the bright light, it takes 10 radiant damage. For the duration you have advantage on saving throws against spells cast by fiends or undead. Once you use this feature, you can't use it again until you finish a long rest.
RollQuest ships the D&D 2014 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.