Evil Uncle: Jesse's grandmother Marie L'Angelle was Allfather D'Aronique's aunt. It turns out that one of the reasons the Grail leadership supported Starr's pursuit of Jesse was because D'Aronique wanted to punish Jesse for killing his "Aunt Marie".
Everyone Calls Him Barkeep: We never do learn what he was called before he took on the name "Arseface". All we can say for sure is that his last name is probably Root.
Happily Failed Suicide: Arseface tried to kill himself because he was sad and lonely, and his idol Kurt Cobain and his only friend had both just killed themselves and the friend had told him to do the same. After the failed suicide attempt, he does all he can to turn his life around, but can never get away from his face being horribly mutilated by the shotgun blast that so fortunately missed his brain.
Does Not Know His Own Strength: He's well-aware most of the time, but in the past, smacked a woman across the face, breaking her jaw. The shock on Cassidy's face implies he didn't mean to go that far.
Exposition of Immortality: He's a vampire and was made one during the Easter Rising in Dublin 1916 at the age of 16. He tells Jesse all about how he was turned and how he came to America and all the friends he's left behind and lost to old age through the years during a long conversation on top of the Empire State Building. Turns out he missed a few details, though.
Karma Houdini: After all of the skeletons in his closet are revealed at how much a monster he is, he pulls it off by making a deal with God to capture Genesis. The last pages show him alive, with his curse removed. To be fair, he also demanded that Jesse would survive no matter what happened as one of the conditions. He also lets himself burn to "death" in the sunlight. Before that, he let Jesse beat the shit out of him. It doesn't really make up for everything he did in the past, but at least he doesn't get away without some pain.
He's also going to have fun dodging the many enemies he made around the country when he was too strong to care, now that he's relinquished that super-strength.
Our Vampires Are Different: Loves garlic, is unaffected by holy water and crosses and survives decapitation. He can also enter a church, can't turn into anything, and doesn't need invitations to enter anyplace. He doesn't even have any fangs, just regular teeth. The sun's a killer, though.
"I tried (turning into a bat) once. Broke both my legs."
God Is Flawed: It is eventually revealed that all of the world's problems are caused by being created by a guy who grew up in total solitude (because there wasn't any universe yet!) and thus developed what could be considered a narcissistic personality disorder as well as any number of related mental problems.
Butt Monkey: Undergoes a Humiliation Conga like no other. At the time of his death, this is the sum total of his injuries (deep breath:) One of his eyes is blind, one of his ears was shot off, a scar was carved over his head making it look like a gigantic penis, cannibals ate his leg and a rottweiler bit off his genitals. Oh, and he's bald and has a harsh voice, too. Since childhood. He literally becomes this when he is anally raped by Bill Glover.
Compensating for Something: After losing his genitalia Herr Starr feels the need to get a bigger gun. And then stand in front of a mirror with it, muttering "Doomcock. Doomcock."
In a way, that turns out to be his downfall: if he was still using his old nine-millimeter pistol, he wouldn't have run out of ammunition in his final gunfight with Tulip.
Determinator: Hops his way out of the desert on one leg, falling every few steps.
Roaring Rampage of Revenge: Got his scar, voice, and baldness from a childhood incident where a gang of schoolboys cut his eye out with a piece of glass. They all ended up dead before his tenth birthday. This incident got him the job as the Chief Executioner of the Grail.
Exposition of Immortality: The Saint Of Killers got a four-issue mini-series all of his own to tell us about his mortal life in the Civil War and the terrible winter of 1878. He dumps a silver dollar with just that date on the counter of a bar in Gone To Texas, too.
Although it has to be noted that a careful reading of the series shows that the Saint rarely, if ever, kills someone without provocation. There's one possible exception: He kills the Angel who woke him up on Boot Hill, explaining that it was "force of habit." He does not open fire on Hugo Root and his men until Root orders his men to pick up their guns (which Custer has used The Word to force them to drop) and shoot the Saint if he draws his guns. When he is found by two deputies standing at their patrol car listening to the radio (trying to learn anything about Custer) he only says "you boys mind me listenin' to your radio for a spell?" He only kills the first deputy when said deputy starts to draw his gun, and warns the other deputy that he'll kill everyone present if "you don't keep that iron in its holster." It's made clear later that the deputy didn't do as he was told. He only shoots Cassidy after Cassidy refuses to answer his questions and punches him in the face. Even when fighting the tank company in the desert, he doesn't even draw his guns until one of the tank crews fires the main cannon at him, scoring a direct hit. He only kills all the angels in Heaven because the "fools got in my way." Even when facing God, he only says "you got this coming, boy. More'n anyone, you got this coming."
Quick Draw: The Saint of Killers can draw his guns faster than a man can see. He uses this to shut down Jesse's Word the second time they meet.
Saint of Killers: "I'm bettin' I can clear holster 'fore your words hit the breeze, preacher. First twitch I see...that's what I'm gonna do."
Root (about the Saint): Then there's this blur an' the fucker's shootin'.
Meeker: So he drew on you.
Root: Ain't what I said. A blur an' then shootin'. I didn't see no draw.