Phantom Lord may be found in the 3rd through 5th Paradise of Heaven within the Midnight Channel. It will alternate between using Mabufula and Mudoon. Upon being defeated, it may drop a Treasure Cloth. Selling 8 Treasure Cloths will unlock the Flying Kato daggers for Yosuke Hanamura.
Phantom Lords appear more frequently in Heaven's 5th Paradise, and may be accompanied by a Devoted Cupid which will cover their weakness to Electricity with its Blue Wall skill.
In Golden, it appear in Paradise 5 through 7 in Heaven. It may drop Aurora Quartz for trade at Shiroku Pub.