Here are the bodycounts as given in the Sevencylopaedia: additions and corrections welcome.
AVON: a scavenger in Deliverance one of the President's security personnel on Zonda a trooper on UP-Weapon four Federation troopers on Horizon Tynus two of Mori's troopers in Volcano one of the Thaarn's guards on Crandor (Tarrant also shot one, and one of these two was only wounded) four of Shad's guards in The Harvest of Kairos at least two of Bayban's men on Keezarn Shrinker (effectively) and Anna Grant in Rumours of Death Dorian's creature in Rescue two Hommiks and later Pella in Power two space rats in Stardrive a mutoid in Animals a guard on Zerok, at least one guard on the Space Princess four troopers on Betafarl in Warlord and two bounty hunters and later Klyn on Gauda Prime before finally killing Blake himself
36 kills minimum.
BLAKE at least two of Vargas followers, and teleported Vargas into deep space. A trooper in SLD. a programmed guardian in Time Squad an Amagon with an exploding neck collar in Bounty; broke a trooper's neck in Project Avalon; shot two guards on Space World and killed another with a pain-inflicting instrument shot a guard on UP-Weapon the Assistant Kommissar on Horizon Provine in Countdown. two Goths holding Rod captive "Stot" on Star One. On Gauda Prime he was seen to kill the bounty hunter Tando, and shot down a flier containing an unspecified number of gunrunners.
17, plus gunrunners.
CALLY Sherm and another of Bayban's men A Link
3, plus however many were in the Space City gunship.
DAYNA shot two Sarrans dead with a bow (would have killed a third but Avon stopped her) Klegg in Powerplay Mori and a trooper on Obsidian two of Bayban's men with a heat-seeking bomb two troopers in Rumours of Death the General in Traitor (in a hand-to-hand struggle) two of Justin's creations on Bucol-2 four troopers in Games (3 shot, one with a Mecronian throwing knife) shot a guard on Zerok and killed up to three more with a grenade.
17-20
GAN No confirmed kills.
JENNA two of the guardians in Time Squad at least 4 troopers in Project Avalon Molok, by teleporting him into deep space.
7 kills.
SERVALAN Coser and later one of her own troopers with IMIPAK Kasabi through drugs in interrogating her a Sarran Deral and Ginka Hob a number of Grose's men on Sardos Practor, Forbus and Leitz on Helotrix Ardus and Justin in Animals
More than 12. She was also responsible for the deaths of Ensor Jr., Maryatt, Ardus, Zukan, Finn, possibly Gerren and probably Keiller.
SOOLIN four space rats on Caspar a mutoid on Bucol-2 3 guards on Zerok, another on the Space Princess 5 or 6 troopers on Betafarl (one with a dagger-like energy weapon, four with a heavy rifle of some sort, perhaps one or more when first attacked) a technician in Blake's base on Gauda Prime and a Federation trooper soon afterwards
16-17 kills.
TARRANT three of Klegg's men one of the Thaarn's guards (though that might have been Avon) two of the Ultra Grose and Lector on Sardos Vinni a Link on Terminal two troopers in Games Investigator Reeve on Virn a guard on Zerok and another on the Space Princess a trooper on Gauda Prime
15-16 kills
TRAVIS A Phibian on Aristo A clone of Blake Gan a trooper at his court martial Nagu and Ven Glynd Cevedic and henchman
Just 7, even including the phibian.
VILA one of Vargas' followers a trooper in Games
2 (but then he doesn't like personal violence)
Neil