SOLO MODE : Wrath of the Emperor's Chosen (kept your name hope thats ok)
the Adeptus Astartes are the finest warriors of the Imperium and are more than willing to show it to those foolish enough todare oppose the emperor. Once per combat the battle bother may attempt an assination of an equivlent (or better) foe whos wounds have dropped below its toughness bonus after adjustment for unnatural statsitic. this strike is in the place of a standard attack that cannot be dodged or parried, no damage is rolled however a relevant ability test(WS/BS/S/AG) is requirerd (type decided by gm and role playing of the kill). the target must pass an toughness test with no modfication from unnatural statistic with a penalty equal to the battle brothers degress of success on the skill test (in groups of -10, i.e. if the battle brother gets 3 degress of success on his agility test then the carnifex suffers a -30) , if the battle brother is a Death Watch Champion or weilding a toxic weapon (that the enemy is vunerable to) this test receives a further penalty of -10(stacks to a max of -20). Successfull assinations yeild 1d5 wounds recovered and the battle brothers rank in fatigue is removed. finnally the kill adds .25(in all cases round down) coheision per battle brother that saw the glorious kil(in LoS), this amount may not exceed the cohesion cap, further if the kill is a stolen kill, then it may cause coheision damage in the same amount or other party strife at the gms discresion.
this ability improves at rank 4 to .5 coheison per battle brother in LoS and the heal improves to 1d5+ rank/2. at rank 7 1 coheision per battle brother in LoS and the heal improbes to 1d5+rank further this ability may now be used TWICE per combat.
failure to connect should result in the attack/ability being spent. if the target passes the toughness test it will become invigorated seizing the innitative by taking a turn immedately and gaining wounds equal to the total of the battle brother attempting the attack, not to excceed its starting total.
tried do a full write up like a book to add legitimacy. let me know what you think.
witty i dont know how your table plays out but at mine theres been a consistent problem of under whelming or extreme hits on the players forcing a "just hide till anything with a good gun is dead" attitude. this solo mode i think will help the flow of wounds stay favorable toward the players and encourage them to engage in more ways than "get behind that rock and spray bolt rounds at the big guy!"