Captain Titus Valerius Captain Remus Astraeus Captain Lucius Corvus Captain Aurelian Falco Captain Lysander Aximand Captain Marcellus Severus Captain Darius Valens Captain Fabius Bile Captain Rogal Dorn (While technically a primarch, this name fits the style and could be used for a character inspired by him) Captain Vulkan Heir (Similar to above, referencing a primarch for inspiration)

These names attempt to capture the Imperial Fists' aesthetic, incorporating elements of Roman names and a sense of gravitas befitting a Captain. They vary in length and sound to offer a range of options. Remember that the Warhammer 40k universe is vast, and many other fitting names could be generated based on specific sub-factions or personal preferences within the Imperial Fists.