Advanced format ruling
Cosmic Horror Gangi'el
Card effect (current official text)If you're Tributing a monster on your side of the field that is owned by your opponent, this card can be Normal Summoned with 1 Tribute. Once per turn, you can place 1 A-Counter on a monster on your opponent's side of the field. (If a monster with an A-Counter battles an "Alien" monster, it loses 300 ATK and DEF for each A-Counter during damage calculation only.)
Current rulings for this card are maintained by Konami.
Rulings data courtesy of Format Library — formatlibrary.com. Spotted an inaccuracy? Flag it in the Advanced forum — sourced change requests get reviewed.