u/Jazzlike-Swimmer-154

The core concept of a Priest as opposed to a Cleric would be that it would lean more into being a back-line caster. IE d6 Hit Dice, no armor proficiencies, very limited weapon proficiencies, possibly INT as their casting stat. At which point the discussion becomes what class features they would need to balance out those nerfs. Me and my brother were talking about it, and we came up with a few that I thought were interesting enough to be worth mentioning.

• Level 1: When casting a leveled spell on an allied creature, the Priest can, as a bonus action (maybe reaction?), add extra Radiant OR Necrotic damage equal to their casting modifier to that creature's next weapon attack, or give that creature Temporary Hitpoints equal to 1d10+Priest level, rounded down.
• Level 6: The Priest can cast spells with a range of Self on an allied creature within 30ft (upgrade to 60ft at a higher level, maybe 14th?)
• Level 10: Once per long rest, the Priest can cast a Concentration spell without needing to Concentrate on it, so long as it is on the Priest spell list and is of a spell level that is equal to or lower than half their proficiency bonus, rounded down (This is the one that has the potential to be the most problematic, to my eyes. I'd be fine making it worse, but it's such an interesting concept that I'd hate to have to scrap it entirely).

I haven't thought of anything regarding subclasses, or the levels at which subclass features would be, so the levels I have listed are entirely malleable, and mostly so that I can show the order in which the Priest would unlock them.