/arena/cosmetics

{
    "response": {
        "success": 1,
        "count": 42,
        "items": [
            {
                "cid": "skin_cardboardknight",
                "type": 1,
                "owned": true,
                "unlock": {
                    "met": true,
                    "progress": [{"counter": "arena_season_wins", "value": 5, "target": 5, "met": true}]
                }
            }
        ]
    }
}