During the adventure Valley of the Brain Collectors the party meet a marooned alien trying to extract vengeance on her former mind flayer torturers. In the original adventure the alien is a kasatha but since I have rethemed the entire Iron God Adventure Path vessel to a more Rogue Trader/Warhammer 40k vessel as opposed to a Star Trek/Enterprise I had to change this alien as well and decided on a Sister of Battle as that works well with the overall backstory. Here is an initial draft of the NPC. She will most likely be CR 10 not 8 and join the party temporarily to meet the Lovecraftian threat of the mind flayers.
Armour Class 17 (+1 aurumvorax hide armour of invulnerability)
Hit Points 182 (14d8 + 70)
Str 20 (+5) DEX 18 (+4) CON 20 (+5)
INT 14 (+2) WIS 14 (+2) CHA 16 (+3)
Saving Throws Con +8, Int +5, Wis +5
Damage Resistance poison and psychic
Condition Immunities disease, fear, frightened as well as advantage on blindness related saves.
Senses passive Perception 15 and has advantage on perception checks
Languages Gothic (High and Low)
Challenge 10 (3,900 XP)
Burn the Heretic. Izumi has an affinity for fire. All fire based attacks she makes have their die increased one step (i.e. d6 becomes a d8, d8 becomes a d10 etc).
Emperor’s Deliverance. All allied creatures within 10 feet (same combat zone) as Izumi gain +2 to all saves as she intercedes on their behalf in supplications to the God-Emperor.
Machine Cult’s Blessing. Izumi has multiple implants to enhance her natural abilities and that also add several resistances and immunities.
Miracle. Izumi petitions the Emperor for his healing power. As an action Izumi may heal a target she touches up to 50 hit points. This pool of healing my be used separately or all at once. Alternatively, she can expend 5 hit points from her pool of healing to cure the target of one disease or neutralize one poison affecting it. Once the pool is exhausted she may no longer perform miracle until she has had a long rest.
The Emperor’s Wrath. As a bonus action once per day, Izumi can cause her weapon attacks to magically deal an extra 10 (3d6) radiant damage to a target on a hit . This benefit lasts until the end of the turn.
Vow of Enmity. As a bonus action, Izumi can utter a vow of enmity against a creature she can see within 10 feet of her, Izumi gains advantage on attack rolls against the creature for 1 minute or until it drops to O hit points or falls unconscious.
Emperor’s Fusillade. Izumi can make two Godwyn-De’Az Pattern Bolter attacks or three Thule-alloy combat knife attacks per attack action.
+1 Thule-alloy Combat Knife. Melee Weapon Attack: +9 to hit, reach 5 ft., one target.
Hit: 8 (1d4 + 6) slashing damage. This is a magic weapon attack.
+1 Godwyn-De’Az Pattern Bolter. Ranged Weapon Attack: +8 to hit, range 50/150 ft., one target.
Hit: 13 (2d8 +5) piercing damage. On a critical hit the weapon does an additional 10 (3d6) explosive (fire/piercing) damage to the target and all creatures within melee range. This is a magic weapon attack.
Relentless. Izumi can move after making an opportunity attack and attack again.
Inferno grenades (6); Aurumvorax Skin Armour (+1 invulnerability Studded Leather armour), +1 Godwyn-De’Az Pattern Bolter, +1 Thule-alloy combat knife (2), filter mask, batteries (7), Admantine Aquilla (Imperial Cult Icon)
A no-nonsense tactician, Sister Superior Izumi had command of the Adeptus Soriatas kill-team sent to support the rogue trader Drub has he pursued the xenos star fortress that fled into the Halo Stars. That mission went awry when a xenon boarding action sent most of the crew insane causing wide scale mutiny. The vessel was eventually recaptured but not without extensive loss of life – too much to allow the ship to continue to function. Against her better judgement she turned to the ships machine spirit which was a heretical device from the dark age of technology more an animus spirit than a servitor. However her mission was still to follow and ultimately destroy the xenon vessel. With the aide of the machine spirit known as unity and the many servitors and robots on the vessel they managed to pursue the xenon vessel to an unknown region of space and unknown planet.
She is absolutely determined to successfully locate and destroy the xenon ship in the Pangaea system. She acknowledges the overwhelming odds, so she attempts to leverage every possible advantage to ensure that the Imperium can triumph as quickly as possible. Though she is fiercely devoted to the Emperor, she is pragmatic enough to accept that faith alone is not enough. Instead, she constantly evaluates every resource at hand. Something she learned when she was an Inquisitorial aide for a decade.
She reviews every debriefing report and new bit of intelligence with this same care. As she assembles this information, she also views the information itself as an asset that must be carefully dispensed. While those under her authority must understand the dangers they confront in order to achieve success, she also realises that at times, she must withhold select information to manipulate her charges into taking paths that are better for the Mission.
After being awoken to the nightmare of the xenos having captured her and her team she has vowed revenge on those who have destroyed her team, the location and destruction of the xenos vessel and aliens no matter how long it takes.