Mysterious Pack Lv. 10
Compound it with Mystic Crystal to obtain Mystic Pack Lv. 11. <Craft> +8 Artifact Pack Coupon <Limited craft> Pa'agrio's Earring Lv. 3 (1 pc.) Eva's Earring Lv. 3 (1 pc.) Sayha's Ring Lv. 3 (1 pc.) Maphr's Ring Lv. 3 (1 pc.)
Not dropped by monsters.
Cannot be spoiled.
The chances are official (x1). On servers with x10, x100 and higher rates, drop and spoil come more often.