I just noticed I forgot to do the crystal war version of Blueblood so here he is.
 
Princess Celestia’s nephew, since a young age he saw his aunt, the great heroine who protected ponies for centuries as a model to equal ; for that purpose, he decided to be the best in everything a noble could including diplomacy, strategy and even swordmanship, but unlike his aunt who’s humble and close to her people, he became vain and self centered.
 
When the war started, he was apointed general due to his great strategic skills and helped to win a lot of battles. 
The war also had an unexpected effect on him, seeing that even the lowest pony was doing their best and after a soldier died to protect him from an assassination attempt, his view of those of lower rank started to change, he still was arrogant and self centered but he considered that as someone superior he had to protect those that are lower than him and not the opposite.  
He even, despite the danger and his fear to get messy, lead an attack against an heavily armed fortress when his soldier refused to go, saying it would be impossible.
 
He met his end at the hands of king Sombra after he tried to lure him into a trap, his soldiers were killed by Sombra’s while he fought with the king ; during the fight he managed to lightly cut sombra’s face, enraged that he havs been hit, Sombra then killed off Blueblood. 
In his last moments, the prince lamented that Celestia was like the sun and stayed out of reach no matter how high he would get but rejoiced that he still accomplished something by hitting Sombra thus proving that he was not invincible like he claimed to be and if he was able to do it then other will be.