From 1d4chan

Okay so Meros, apothecary of the 9th Company under Captain Furio of the Blood Angels during the Horus Heresy, is probably THE MOST BAD-ASS of all Blood Angels. He not only saved his own Primarch from eternal damnation to the forces of Chaos, but also met his gene brother from TEN THOUSAND YEARS IN THE FUTURE (Brother Rafen). Alright, so this hero of heroes was just a line-Astartes and a junior Medicae and was tasked by First Captain Raldoron with the removal of the progenoid glands of Brother Alatros who had succumbed to the Red Thirst, which at that time was a secret held by Sanguinius and only a few other Blood Angels (and Horus, the sneaky bastard). He was told never to talk about what he saw and witnessed Raldoron painting Alatros' armour black, he spoke the words: "You are in the company of death. I hope you find peace there", foreseeing the Death Company.

Later, during a war with Dark Eldar, the Thunderhawk that Meros was in was shot down and he slipped into a coma. Two of his squad mates placed him into one of the exsanguinators, the Blood Angels coffins used for transforming a Neophyte into an Astartes. The intent was to drain out the poison from his blood and replace it all with fresh blood. During this weird, blood induced future-sight hippy trip, Meros met Brother Rafen, current (our present 40K), Meros's future (it's complicated), Sergeant of the Blood Angels Chapter who has the same gene-seed as himself. Suddenly they realized that the Sanguinor was there with them and a whole bunch of crazy shit happens and Meros and Rafen have to fight a horde of phantoms and vanquish them with little effort. Realizing the magnitude of meeting his gene-ancestor, before being pulled from their separate but parallel blood comas, Rafen uttered a single warning, a curse: Horus. When Meros awoke, it was to find his Legion being called to the Signus System by Warmaster Horus. And just like that, Meros's butthole tightened into untrust for Horus and knew that bad fucker was up to no good.

Now after all the crazy shit goes down on Signus Prime and Sanguinius and a small strike force have broken into the Cathedral of the Mark, the greater daemon of Slaanesh, Kyriss, had helped to create a cursed artifact of pure rage. The daemon made a deal with Sanguinius that all he had to do was give himself over fully to the rage and corruption of the artifact and Kyriss would cure the Blood Angels of the Black Rage and Red Thirst forever. Seeing that his Primarch was actually considering accepting, Meros leapt into the artifact instead, followed by his loving father Space Jesus. Inside this realm of Chaos that was the artifact, Meros refused to let his Primarch take the deal, so he CUT OUT HIS OWN GENESEED and gave it to Sanguinius before letting the Rage overtake him. He sacrificed himself for the most beloved Primarch in the Imperium, be thankful!

Meros the badass apothecary was dead, and The Red Angel was born. Not that pussy Angron. The Red Angel was a being of pure rage (seriously, the motherfucker was literally on fire). He even told everyone if Angron had a problem with him taking Angron's title then Angron could come try and take it from him! (Angron never gave a fuck, considering he hated said title).

(Had Sanguinius been corrupted both he and the Blood Angels would have been lost. Horus would have won the Heresy!)

Famous loyalist members of the Adeptus Astartes
Black Templars: Grimaldus - Helbrecht - Sigismund - Tankred
Blood Angels: Acrion - Astorath - Corbulo - Dante - Donatos Aphael
Erasmus Tycho - Karlaen - Lemartes - Mephiston - Meros
Moriar - Rafen - Sanguinor - Thalastian Jorus
Blood Ravens: Apollo Diomedes - Avitus - Azariah Kyras - Brother-Sergeant Matiel
Cyrus - Davian Thule - Force Commander Aramus - Gabriel Angelos
Indrick Boreale - Isador Akios - Jonah Orion - Martellus - Tarkus - Thaddeus
Crimson Fists: Alessio Cortez - Alexis Polux - Pedro Kantor
Dark Angels: Asmodai - Azrael - Belial - Corswain - Ezekiel - Lazarus - Luther - Naaman - Sammael - Zahariel
Flesh Tearers: Gabriel Seth - Nassir Amit
Grey Knights: Anval Thawn - Arvann Stern - Castellan Crowe
Hyperion - Kaldor Draigo - Vorth Mordrak
Imperial Fists: Darnath Lysander - Slaughter Koorland - Maximus Thane
Tor Garadon - Vorn Hagen
Iron Hands: Malkaan Feirros - Kardan Stronos
Lamenters: Malakim Phoros
Minotaurs: Asterion Moloc - Hecaton Aiakos - Ivanus Enkomi
Mortifactors: Artemis
Raptors: Lias Issodon
Raven Guard: Kayvaan Shrike - Korvydae - Kyrin Solaq
Red Scorpions: Carab Culln - Casan Sabius - Sevrin Loth - Sirae Karagon
Red Talons: Autek Mor
Salamanders: Adrax Agatone - Bray'arth Ashmantle - Tu'Shan - Vulkan He'stan - Xavier
Space Sharks: Tyberos the Red Wake
Space Wolves: Arjac Rockfist - Bjorn the Fell Handed - Bran Redmaw - Canis Wolfborn
Haegr the Mountain - Krom Dragongaze - Logan Grimnar - Lukas the Trickster
Njal Stormcaller - Ragnar Blackmane - Ulrik
Ultramarines: Aeonid Thiel - Antaro Chronus - Captain Titus - Cato Sicarius
Illiyan Nastase - Marneus Calgar - Ortan Cassius - Severus Agemman
Torias Telion - Uriel Ventris - Varro Tigurius
White Scars: Kor'sarro Khan