2024 · ソースブック（プレイを拡張するルール／オプション）
The Fiend-Sage of Rel Astra
This four-page Greyhawk mini-supplement details an enigmatic fiend serving Prince Drax of Rel Astra. A cultured scholar and formidable molydeus tanar’ri, the Fiend-Sage possesses extensive knowledge of the lower planes, the Flanaess, and arcane matters. The supplement includes the Fiend-Sage’s lore, a complete stat block, a timeline of its activities, and guidance for using it as a warlock patron. It also provides notes on tieflings in classic World of Greyhawk campaigns, adventure ideas involving conflict or alliance, and accompanying artwork.
属性／ステータス制（STR、CON、PERなど）レベル制（XPを獲得してレベルアップ）ダイス（主にd20）
ゲーム情報（人数、プレイ時間、対象年齢、クレジット）の出典：BoardGameGeek。