Modified Storm Bolter, The Searing Blade
Fire manipulation, telekinesis
Life on Nostramo
Little is known about what Haak's childhood consisted of, other than he had set his sights on becoming a defender of his homeworld and was eager to join forces with the Emperor of the Imperium of Man as their great crusades began. Beyond this, the finer details are as well hidden as Nostramo itself once was, permanently shrouded in darkness by its moon.
The Adeptus Astartes
Haak's prowess in battle earned him respect quickly with his brother-marines--a term coined by the Adeptus Astartes themselves that applied to every man in their organization who served and fought alongside them as a Space Marine of the Imperium--he began rising in rank quickly. Quickly enough to be noticed by a separate organization entirely. It was they who contacted him and warned him of the events to come.
The Horus Heresy
The Horus Heresy was the darkest period in the history of the Imperium - but Haak and those loyal to him were spared from its corruption and bloodshed, as they were taken under the wing of The Flame Knights.
Tutelage under the Flame Knights
A separate and reclusive order whose goals are not even wholly revealed to most of their own, little is known with any degree of reliability about the Flame Knights. They saw fit to recruit Haak for their cause, eventually ordaining Haak as a Flame Knight in his own right. Haak never returned to that region of space - at least not in that time period. Whilst training and running missions for his new order, Haak discovered quickly that time travel was no difficulty for them.
The Suburban Senshi
Haak has fought to defend the Earth on several occasions, often with the aid of (or sometimes because of) his dealings with the residents and visitors to the Suburban Senshi's main residence. He now lives in Tokyo as well, married to Euri with two children, Hachi and Silver.
Until very recently he'd been absent for a significantly long time. He's returned again in one piece, arguably in better condition than he left, but has said little about his reasons for leaving, other than it was the only choice at the time.