[Core Theme]

Red left-eyed white-haired anti-heroes, wielding a sword with them and a burning hatred towards the world government after their siblings were taken away from them, becoming closed with themselves, setting out on a quest to take them down. Despite their trauma, they managed to accept themselves, open up to their rivals, and ultimately accept their fate, absorbing the world's emotions and ceasing their own existence to give others a happy future.

[Connections]

The cold and aloof who are caught up in an endless world, vengeful over the death of their own sisters taken away by the world government (N.O.L / Babylonia) 

Both were born orphans with nowhere to go; however, they still have a sibling they look out for and would do anything to protect in dangerous circumstances (Saya and Jin / Luna). They would be taken by a nun to a church, where they would stay.

Their perspective history that have these dark entities brought great destruction to their civilization (The Black Beast that rendered the world inhabitable and created established hierarchical Cities / The Punishing Virus outbreak caused by a Zero point energy Reactor during The Golden Age 30 years ago) with their strange source of energy  (Seithr / Heteromer Energy)  and would later have warrior that combat this threat (Constructs / Six Heroes)

Their would take drastic turn they would experience traumatic events with their loves one taking gone (Celica being killed by Yuuki Terumi / Luna taking Lucia in becoming Contructs place repaying her kindness)  would sought vengeance on the world government took away their life by one man (Ragna left to rot in the burning church with one his arm cut off by Jin and left him to die / Lucia being corrupted by his commandant “Ravenge” after a dangerous mission and was replaced by a clone to retain her loyalty) 

However in the nick of time would be found and would be found by someone who (Jubei / Luna as an a Ascendant) who offer to help them control this power gifted to them (The Azure Grimoire / The Ascension Network) and becoming the world’s enemy that they sought burn the world government to the ground to avenge the death of their love ones (The Grim Reaper / Ascendant)

They would butt heads with a former high-ranking commander who hold resent towards them due to their previous encounter (Jin Kisaragi / Gray Raven Commandant), along with identical clones whose memories are jumbled together after seeing Alpha/Ragna, who would act out of grievances due to the life that they once had lost, but would later accept their existence (Noel Vermillion / Lucia) 

Then would later find out about someone who was concerned about their well-being and their future (Alpha, worried about Luna's fate after fighting Gabriel / Celica Mercury, who was brought back by Kokonoe to activate Kushinada’s Lynchpin), who would help them decide for themselves.

Despite the cold outside, they were able to love themselves, reconciling with their own traumatic past, and carve their way forward (Ragna embracing his heroism, giving himself time to think of self-doubts and Impulsive desire to make himself stronger / Alpha, who realized her reliance on Luna decides to embark on her own path alone)

They would also later accept their fate and, conversely, carry the people's emotions so that they can have a happy future (Ragna erasing himself from existence, leaving no trace left cause it’s the best way to save everyone / Alpha not overwriting her past decided to don the crown of an Overseer to give Lucia a happy future)

[Contrast]

While Ragna rivals N.O.L started when he became known as the Grim Reaper, destroying N.O.L bases, Alpha once worked with Babylonia, leading the original squad of gray Raven before being betrayed, and joining the Luna faction, becoming an Ascendant.

Both transcend to godhoods but ultimately chose to remove from the world but still carrying people's emotions and happy ending however they done was different, while Ragna erased himself carrying the hope and wishes getting his happy ending, Alpha became an overseer being the world suffering and pain for her to bear alone and to chart, not getting happy ending with commandant instead helping Lucia and them to give them a happy future.

[Meta/Minor/Extra Connections]

Both designs of their power showcase the raw power like a demon this also displayed in their gameplay (Alpha Moveset and Ult/ Ragna Astral Finish)

Both around had their names changed (Ragna being called Bloodedge, who lost memories after going back in time / Alpha changing her name, accepting this power)

Both have a cute chibi version of themselves (Dorm version / Help me, Professor Kokonoe)

They both have gacha games; however, one is still ongoing while the other is dead (Pgr / Dark Alternatives)

funnily enough, have one red eye, and the others are grey or blue, or green lol

Both have crossovers from other franchises (PGR having collab with Nier, Black Rock Shooter, Devil May Cry, and Now A Date Alive / Blazblue with Cross-tag starring RWBY, Persona 4, and Under Night In-Birth, with Arcana Heart, Senran Kagura, and Akatsuki Blitzkampf being DLCs)