Thanks all for your answers.
Here is another attempt:
Plague Marine, Advanced Archetype
+10 Toughness, -5 Agility, +15 Corruption, +9 Infamy
Common Lore: any
Forbidden Lore: Daemonology OR Forbidden Lore: Heresy
Scholastic Lore: Chymistry
Scholastic Lore: Chymistry +10 OR Trade: Chymist +10
Nurgle's Blessing: Within their massive and disgusting Power Armour their bodies are bloated with disease, swollen with corruption and rank with decay even as they no longer are capable of feeling pain, the greatest mutational "gift" given to them by the Plague Lord. The Plague Marine gets Unnatural Toughness (+1) trait and once per combat encounter, a Plague Marine may spend an Infamy Point to get the Regeneration (4) trait for 4 Rounds. Moreover, the character cannot be harmed by diseases, poisons or toxic effects.
Child of Toxicity: The body and armor of the Plague Marine is filled with toxins, diseases, poisons and bacillus. At the cost of one Infamy Point, the character can exude the toxic properties of its own body during its melee attacks. All his melee attacks benefit of the "Toxic (+0)" Quality for the duration of the combat. The character can spend up to 2 additionnal Infamy Points to gain the "Toxic (1)" or "Toxic (2)" Quality, for respectively 1 and 2 Infamy Points.
Aligned with Nurgle.
I first added a willpower bonus because Plague Marines are Fearless in the tabletop game. But the Talent Fearless works better so i can skip the willpower.
Then, a +10 bonus to Toughness seems appropriate, but since it's, imho, more powerfull than 2 boni in 2 different characteristics, i would put a -5 in Agility. There might be no precedent for that, but in the tabletop game, Plague Marines have an initiative of 3 instead of 4. So, it seems appropriate.
More wounds seems to be on the right way. I put 19+1d5. Maybe too much?
I slightly adjusted skills (now has both Scholastic Lore: Chymistry and Trade: Chymist, and has one at +10).
For talents, i kicked out the fighting talents and added True Grit. I think it's important to keep Fearless if i wanna mmake the plague marine on part with its tabletop equivalent. But True Grit fits the concept very well too. So, it's down to only 5 talents, but 2 of them are rank 3, so it should make it ok. Any thought?
Now, the most difficult part is the special abilities.
I think an ability making the Plague Marine immune to diseases and poisons is mandatory. I considered to give him the Trait "Undying", but it's slighty out of concept, with the ability not to need breathing.
So, i just give him an ability inspired by the first part of the trait Undying.
I like the suggestion of BrotharTearer, and used it, just reducing the regenaration amount, to compensate for the immunity to diseases and poisons.
I modified the "Child of Toxicity" ability to make it requests the use of Infamy point(s).
Any opinion on this new version?
Edited by Tristelune, 04 January 2014 - 02:30 AM.