Whilst active, Vladimir's blood crystallises inside his blood vessels, boosting many of his physical capabilities substantially rather than instantly killing him; furthermore, the rate at which he generates this blood is greatly increased, and he can forcibly expel it from his body and control it remotely for both offensive and defensive purposes. He has yet to establish the entire breadth of purpose it has, but so far he has figured out that this crystallised blood is rather tough, able to take quite solid hits without breaking, and can be further enhanced by deliberately channelling his aura through it; it can repair injuries to his person far larger and far faster than his Aura alone could, restoring flesh and skin to normal rather than healing them as scar tissue; and it is generally non-conductive to both electricity and temperature, making it difficult to electrocute, burn, or freeze his body or his blood. And, of course, he cannot bleed out whilst BotD is active. Crystallised blood does, however, have to remain connected to him at all times, and will immediately revert to normal blood if forcibly separated from his person or if his Aura runs dry.
Notably, something interesting happens if he injects himself with, or otherwise places into his bloodstream, a certain quantity of powdered Dust (in solution with a liquid such as water, typically) shortly before activating BotD: its usual insulative properties will be overwritten, and his blood will instead take on elemental properties similar to the type(s) of Dust injected. He will therefore frequently use this trick to amplify his Semblance before combat when he thinks it's needed, and he does in fact have auto-injectors covertly installed in the handles of his weapons, typically containing Ice Dust as standard, but capable of containing whatever Dust type is appropriate for the opponent he is facing, just in case he needs a mid-fight boost; whilst this can provide interesting effects such as freezing, burning, or shocking flesh on contact or becoming (even more) nigh-invulnerable due to having rocks for blood, it can also lead to serious health problems if he isn't careful with quantities, or if he lets the injected Dust sit in his bloodstream for too long without activating his Semblance in order to use it up.

Vladimir was born into a moderately aristocratic Atlesean family which had recently fallen on hard times. His father, also called Vladimir, was a member of a group called the Knights of the Dragon that had been quite famous in the nation of Mantle before it ceased to exist, but which had since declined to the point of near-dissolution; despite this, he retained the honorary surname "Drakk", or Dragon, and so his son held the surname of "Drakka" or Dragonson, in addition to the family surname of Plasimov. This state of affairs had not sat well with Drakk, or his high lifestyle and funds, and he thus began abusing his wife both physically and mentally, until finally overdoing it and accidentally putting her in hospital for long enough that questions were asked about him. This ultimately triggered Drakka's removal from Drakk's overbearing mannerisms, though these had already left in the twelve-year-old the beginnings of his own rather cruel, if highly intellectual personality; as a final request, Vladimir's father asked the authorities that, rather than being put into foster care, he be sent to live with some close family friends, the Morgensterns.
Unlike the Plasimov family, the Morgenstern family had done very well for themselves in spite of their own allegiance with the Knights of the Dragon. Seeing what his father had declined to, and comparing his own possible future to that if he didn't make his moves quickly, Vladimir made it a personal goal of his to usurp the biological heir to the Morgenstern's fortune, and thus to surpass his own father in every way he could. He started to sidle himself into the family patriarch Valentine's good graces as quickly as possible, whilst simultaneously engaging in psychological warfare against his step-brother Jonathan to throw him off and have him lose face at times when it would matter. He might have succeeded, too, if not for two significant factors: Valentine was a lot more perceptive than Vladimir gave him credit for, often figuring out the truth of Vlad's manipulations with little obvious effort; and, more importantly, Jonathan was not as much of a doormat as he first appeared. Despite Vladimir's best efforts to avoid direct conflict, the two teens came to blows far more often than he'd like, and these fights quickly drew out both of their innate potentials. Deciding that he would rather they make use of their developing Auras against the Grimm than against each other, Valentine enrolled both children at one of Atlas' private combat schools, in preparation for them to eventually enrol in the famed Atlas Academy itself.
This to some extent quelled their battles for the time being, since illegal combat was far more harshly punished by the school than by their father, but Vladimir nevertheless continued to bully Jonathan at any opportunity he got, leading to little good blood between them. This unstable peace ended after Vlad finally unlocked his Semblance, granting it an appropriate name in the process: Blood of the Dragon. He spent the final year or so of his education at the school training his Semblance and figuring out what it could do with little intimidation toward Jonathan; then, the very day after officially graduating from the school, he made a point of beating his stepbrother to a pulp with his bare hands in public, getting himself arrested and his brother hospitalised and in a coma.
Though Valentine somehow managed to salvage both Vladimir's future and his own family name, it was clear the moment he brought Vlad before him that the adopted child had gone too far: he was officially disowned, and would never see a penny of the Morgenstern fortune so long as Valentine had any say in the matter whatsoever. With that announcement practically ringing in his ears, the astounded teen was dispatched to Atlas Academy, having already vowed to make himself the academy's top student, and from there to become a living legend with or without the Morgenstern fortune, or else die trying, for nothing less than this would satisfy his ego.