So I have just started playing like about a year and a half a go I have always want to play a grim reaper but every time I tried to make one it ended horribly and i just want to know if any of you have make one and would like to tell me how and what I will need to play it and make it but if have all ready make one can you give me the Character sheets for it what i will need to play it and thank to who ever can help me  in endeavors to play a grim reaper

I think Gythanki, Criminal Background, Divine Soul Sorcerer, have a connection to Vlaakith the Lich Queen and go out finding souls for her whilst tryingto ind a magical sword..... Its a bit of a stretch but here's the reasoning:

From game mechanics point of view:

Githyanki (from Mordenkainens Tome of Foes and I think there is a UA for it as well)  lets you start with light & medoium armour proficicency and proficiency with short sword, longsword and great sword. Use a Great Sowrd instead of homebrewing a Scythe and aim to look for a Githyanki Silver Sword or a Vorpal Great Sword and let your DM  know this is something of a goal they have been tasked with or it maybe your punishsment for losing it in the first place hence explaining why they are on the prime material plane. If you can start with half plate armour then even better.

Criminal background gives you some basic rogue skills which is useful for when phasing through a wall isn't required.

Divine Soul Sorcerer gives you access to both Cleric and Sorcerer spelllists to flesh out grim reaper style spells and abilities such as Bane, Etheralness, Misty Step, Finger of Death etc and keep a few party friendly spells such as Counterspell, Cure Wounds, Bless  etc.

The point of the character is then to be a 2nd rank healer/caster/fighter/rogue, you step into whatever role the party is lacking. As you fill several roles you have more chance the party will develope an interest in keep ing you alive. And the bonus is you can do all those 2nd rank duties and still act as or be the grim reaper without having to Multiclass.

Cleric Death Domain is exactly what your looking for. It literally says Reaper at first level, and touch of death at second soooo... there you go.

Race I think Fallen Aasimar as it is essentially the angel of death. Grab a Glaive call it a scythe and you are the Grim Reaper.

Tell me what you think....

Quote from Fattsgalore >>

Cleric Death Domain is exactly what your looking for. It literally says Reaper at first level, and touch of death at second soooo... there you go.

Race I think Fallen Aasimar as it is essentially the angel of death. Grab a Glaive call it a scythe and you are the Grim Reaper.

Tell me what you think....

 This is what I was thinking. Almost to a T (I hadn't gotten as far as race).

While I dont particularly like mini-maxing the maths for characters to work out how hard they can hit, I hadn't realised how much damage touch of death does...from 9pts at level 2 upto 45 at level 20! Add that to a Critical Hit and you have some major damage  especially when you add on an extra d8 for their level 8 divine strike and nab booming or greenflame blade via spell sniper or magic initiate for another few dice and that is quite frightening (albeit limited byt number of times a day you can do it).

Assuming using the glaive/scythe you mentioned att level 20 thats something like:1d10 slashing + 1d8 necrotic +3d8 thunder, x2 then  + str mod +45 necrotic damage + another 4d8 thunder damage if the target moves moves, so just using average results on each dice I think you get to 90-100 damage easily. (depending on your Str mod).

I also agree with Death Cleric. They oddly make better necromancers than necromancer wizards.

I also agree with Fallen Aasimar - their necrotic shroud is a perfect fit both aethetically and in feature (+level necro damage), which combined with radiant and necro resistance is just great.

Especially if you want to bring some christianity flavour to it: there are more than angels of death in the bible, the most known / powerful being Samael - Archangel of Death, charged with severing souls from the body when a mortal dies (literally reaping souls) and fell from heaven after bedding Lilith and siring demons.

So Fallen Aasimar Death Cleric is the closest to Grim Reaper you can get without homebrewing.

Spell selection wise though Sorcerer gets you access to Disintergrate, Power Words (Pain, Stun, Kill) and Finger of Death which are a bit more thematically in keeping with a Grim reaper severing the soul form the body with a click of his finger and might be a bit more useful combined with the twin spell metamagic than the Reaper abilities of Cleric Death domain, especially as you can also twin spell healing spells to boot.

Just going to throw out Assassin (Rogue) as a martial counter to the spellcasting options presented above. You'd have to reflavor a weapon, but that pile of sneak attack damage when you emerge from the shadows is nasty.

I made this one harengon reaper just now actually, and he might be one of my favorite characters. 
the story started when my character was ironing his clothes, then slips, causing the iron to fly out of his hand, and kill the reaper standing behind him. Naturally, the rabbit put on the suit a became the reaper himself.

i made my character a Paladin, (due to it fitting the whole service of god thing) and made him chaotic/neutral. (Because the reaper is killing souls to release them)

my opinion: 9/10 character, DO NOT COMMENT FURRY HAREGON.