The other "Trinity" is a set of three spell cards that, if all three were in your opening hand, would cause the opponent to start with only one card in their hand (two after he draws his first card in his/her turn). This makes the turn player that draws them gain massive advantage. The first card of this "Trinity" to get forbidden was "The Forceful Sentry with the April 2005 Forbidden List. In September 2007, the last card of this "Trinity" (Confiscation) was put on the Forbidden List.
In the Anime and Manga, The Trinity refers to "Kazejin", "Suijin", and "Sanga of the Thunder", which are the three monsters needed to summon "Gate Guardian". Later on it was used to refer to "Obelisk the Tormentor", "Slifer the Sky Dragon", and "The Winged Dragon of Ra", also known as the "Egyptian God" cards.