riposte is complicated 
1. Add to the .info file a riposte effect
combat_skill: .id “fearless” .level 0 .type “melee” .atk 0% .dmg 0% .crit 0% .launch 4321 .target .is_crit_valid True .effect “Fearless Riposte 1” “Mark Self” “Berserk”
2. Add to the effects file a description
effect: .name “Fearless Riposte 1” .target “performer” .curio_result_type “positive” .chance 100% .riposte 1 .duration 2 .riposte_chance_add 100% .on_hit true .on_miss true .damage_low_multiply 10% .damage_high_multiply 10% .crit_chance_add 5%
2. Add to the .art file an animation for riposte
riposte_skill: .id “riposte1” .anim “attack_low” .fx “bleed_out” .targchestfx “blood_splatter”
and that should do it