Let's see....
First one: Captain Kamenev Drang, mercenary Gland-Warrior, shock-trooper lunatic former veteran Guardsman. Came with obligatory black greatcoat, severe psychosis, chem-implants, wielding a flanged shock mace, a bolt pistol slightly older than the Imperium itself and of uncertain parentage, occasionally a heavy stubber or a heavy flamer if he could nick it, and then found a Daemon weapon, became symbiotically possessed and got a massive, several-thousand word fan fiction written about him and his Mercenary regiment. Did a series of cameos in Mobius's Star Wars.
Second One: Torquemada Pfeil. Never got off the ground, due to Mobius's excellent RP dying off before it started.
Third one: Some Guardsman called 'Raven', Death Korps of Krieg. Went MIA during a mission, was later found to have disabled an enemy sentinel but been killed by the munitions detonation.
Fourth one: Landsknecht-Captain Torquemada Lucan: Insane aerial cavalry commander, leading a misfit company of aerial cavalry on a campaign to murderise a lot of Orks, support fellow Guard regiments and so on.
Fifth: Lieutenant Monfort Drake: Lunatic Drookian Fen Guard captain, leading a team of commandos by the name of 'Delta Team' (Or basically, a kill-team).
Sixth: Montfort Wellesley: Retired Royal Marine Lieutenant (Well forcibly retired), part of a cyberpunk game between me and my girlfriend. Fun character.