change this
case 8: // curse coma and poison
status_change_start(src, bl, SC_COMA, 100, skill_lv, 0, src->id, 0, 0, SCSTART_NONE);
sc_start(src,bl,SC_CURSE,100,skill_lv,skill_get_time2(skill_id,skill_lv));
sc_start2(src,bl,SC_POISON,100,skill_lv,src->id,skill_get_time2(skill_id,skill_lv));
break;
to
case 8: // curse coma and poison
status_change_start(src, bl, SC_COMA, 10000, skill_lv, 0, src->id, 0, 0, SCSTART_NONE);
sc_start(src,bl,SC_CURSE,10000,skill_lv,skill_get_time2(skill_id,skill_lv));
sc_start2(src,bl,SC_POISON,10000,skill_lv,src->id,skill_get_time2(skill_id,skill_lv));
break;
that means if the death/coma card appeared in the skill, it will have 100% chance of activating coma. if you set 10000 to 5000 you will have 50% chance to activate coma whenever the death/coma card appears
Sekai RO's post in Tarot Card Of Fate's Problem was marked as the answer