Marneus Calgar

"'You once more managed to succeed, on an impossible mission, WHEN YOU SHOULD HAVE DIED!... But NO! You succeeded because you were trained by the book, the holy codex of our OH-SO-WONDERFUL-I-COULD-SHIT-MY-POWERPANTS SPIRITUAL LEIGE!'"Marneus Calgar is the current Chapter Master of the Ultramarines.

Official Canon
Marneus Calgar is one of the best known Chapter Masters in the Imperium, being the leader of the Ultramarines and the Ultramar region of space. During the invasion of Macragge, he lost all his limbs after fighting the Swarmlord, with his entire first company getting killed trying to rescue him. Nonetheless he was able to escape and rout the Tyranids from Ultramar.

Behemoth Canon
During the advent of the Tyranid threat, he was warned about this new alien adversary by Inquisitor Kryptman of Ordo Xeno. Hive-Fleet Behemoth was on its way to Ultramar, intent on destroying it as it had two well-defended planets before. Calgar prepared the troops of Macragge for the confrontation, boosting his troops' morale while being careful not to make too many meta references. He and his brave warriors had a great start against the Tyranid hordes, but everything changed when the Hive-Mind sent a Swarm Lord against the Astartes. After being defeated in single combat by the Swarm Lord, Calgar was left one-eyed, legless, armless and powerless. Though he kept challenging the Tyranids, all he could do was witness his troops getting slaughtered mercilessly by the unfeeling hordes.

The Ultramarine won the Battle of Macragge nonetheless. The Chapter Master's discussion with Kryptman after the battle made the Inquisitor suspicious of the events, but it had become notorious how the Ultramarines won the day that day, as well as any other day of battle since.

A hundred years after the Battle of Macragge, Calgar and his Ultramarines received thousands upon thousands of vox-messages of distress. So much so that their Psykers had seizures from the overload. All begged for their intervention against the Tyranids attacking the planet of Victoria Primus. The Chapter departed and quickly destroyed the xenos upon landing. Marneus Calgar himself challenged the local Swarm Lord. The outcome was quite different from the last with Calgar ripping the fiend's arms off and punching it so hard it passed through multiple buildings and landed inside a taurox that exploded as a result. Afterwards, Calgar beratted Deathwatch and the local forces for being pathetic babies who can't help themselves and who think the Ultramarines are their go-to space-exterminators.

TTS Canon
In keeping with his tradition of always referring to the Ultramarines as "Ultrasmurfs," the Emperor has given Calgar the moniker "Papa Smurf."

Unfazed by losing all his limbs and an eye to the Swarmlord, Calgar decided to call the duel a draw. However, witnessing the horrible destruction, including the deaths of the entire First Company, left a lasting impact on Calgar.

Despite this, the Ultramarines simply won the battle offscreen and for no adequately explained reason. Since that point onward, the Ultramarines have won every battle they've fought in, even if they should have been impossible. Even their past failures seem to have been retroactively altered so as to cover them up. This repeated winning streak has caused Calgar to enter a depression spiral as victory comes too easily now and has lost all satisfaction. He is also bitterly annoyed by the existence of Cato Sicarius, who is constantly trying to usurp him as Chapter Master. Even more, he hates that Sicarius didn't care at all about needlessly putting his men's lives at risk.

Uriel Ventris, one of Calgar's confidents, confesses that he believes something is altering the past in the chapter's favor. Acting suspicious, Calgar vehemently denies this, while claiming he wasn't hiding anything.

The Ultramarines' strange reality-bending competence was demonstrated once again when Calgar was able to easily leap into the air despite wearing bulky Terminator armor, claiming he didn't need a Jump Pack (though this is more of a joke referencing Gabriel Angelos doing the same in Dawn of War 3 despite this being nominally impossible to do with a Terminator suit).