AI Perception Mark player as enemy

Since 4.10 is recommended to use a AI controller as provider of diplomacy options:

class AIMODULE_API AAIController : .... public IGenericTeamAgentInterface

Override method with logics of your game:

virtual FGenericTeamId GetGenericTeamId() const override { return TeamID; }
virtual ETeamAttitude::Type	 GetTeamAttitudeTowards(const AActor& Other) const override;