What?! No Diehard feat in DnD5e? Let’s fix this!
Diehard
You are a solid tower of stone. No blow can fell you unless it would drop a kingdom. Gain the following benefit:
- Increase your Constitution by 1 to a maximum of 20 or gain proficiency on Constitution saving throws.
- When you are reduced to 0 or fewer hit points, but not killed outright, you may make a Constitution saving throw with the DC equal to 5 + half damage dealt. If you succeed, you are instead reduced to 1 hit point.
- Gain advantage on Death saving throws.
Thoughts? Too much? Too little? I’d like to hear what you have to say!
Throat Punch Games 
Advantage on Death saving throws seems a little strong, especially since nothing else in the game can grant that besides someone casting a spell on you. I like the other stuff, but maybe a simple +2 or so would suffice.
I feel feats in general feel a bit overpowered in this addition. Some other feats give you the equivalent of advantage on stealth rolls in armor ( to counter act the disadvantage you normally have.) Although, if more people agree, I would have no problem with downgrading to a +2 instead.
Advantage on death saving throws is a bit much, especially since the only other thing that can grant you something like that is someone casting a spell on you. I like the other stuff, but maybe a simple +3 or so would suffice.
Did you comment twice? Maybe moving to the +3 is better than advantage for this one.
Yeah, whoops! Internet went out for a moment when I clicked post on the first one, so I thought it didn’t go through and retyped it. Apologies.