Temperus Maximus is the Chapter Master of the Angry Marines, by virtue of being the angriest Marine in the chapter, if not in the entire Imperium of Man. He's got a pair of chainfists with assault cannons built in and Khorne is fucking scared of this guy as he reminds him of a certain other angry marine. He is constantly entombed in Artificer Terminator armor, not in order to protect himself, but to protect enemies and allies alike from the sheer RAGE he outputs unchained. He is never seen without the Angry chapters heirloom; an adamantium cigar that none but the living embodiment of the Imperial middle finger can smoke.
It is believed by many imperial citizens that Temperus Maximus is the holy equivalent of a daemon prince since his anger is beyond even the Emperah's comprehension.
Records say that an entire World Eaters Warband ran like little pussies just by the sight of this angry beast and it is unknown how old he is but he's been around for quite a while though, His main goal is to teach the World Eaters just who is the angriest space marines around.