you can give the apex predator skil a buff that says "-200 Acc vs not marked"

Effect example:

effect: .name "Only vs Marked " .target "performer" .curio_result_type "positive" .skill_instant true .buff_ids "marked_only" .on_hit true .on_miss false

Buff example

{
"id" : "marked_only",
"stat_type" : "combat_stat_add",
"stat_sub_type" : "attack_rating",
"amount" : -2.0,
"remove_if_not_active" : false,
"rule_type" : "actor_status",
"is_false_rule" : true,
"rule_data" : {
"float" : 0,
"string" : "tagged"
}
},