20th Anniversary Pack
Double-click to obtain Anniversary Shining Relic Summon Coupon - 11-time (5 pcs.), Solaris (20 pcs.), Aether (200 pcs.) and Hero's Mark (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.