REDU format ruling
Red-Eyes Black Metal Dragon

Nearest-era rulings (Tengu, Sept 2011) — no REDU-specific archive exists.
Card effect (current official text)Cannot be Normal Summoned/Set. Must first be Special Summoned (from your Deck) by Tributing "Red-Eyes B. Dragon" equipped with "Metalmorph".
Rulings
source: Rulings_Tengu (Format Library) — nearest era to REDU (Sept 2011 vs Sept 2012); verify against period sources · 1 era-inappropriate line(s) removedRulings data courtesy of Format Library — formatlibrary.com. Spotted an inaccuracy? Flag it in the REDU forum — sourced change requests get reviewed.