- "They say players that get killed by him never come back to the game."
- — Haseo —
Tri-Edge (三爪痕 or トライエッジ, ToraiEiji) is a legendary PK. It is said that players killed by Tri-Edge never log back in. These victims are known as "Lost Ones". He leaves a three-edged Sign at the location of his victims, and this is the source of his name.
In .hack//G.U., the name "Tri-Edge" has been used to refer to two distinct entities. This misdirection was called The Great Deception by the series creators. The two characters are:
- Azure Flame Kite - A strange PC, shrouded in azure flames, believed to be Tri-Edge by Haseo, Midori, Phyllo, and others.
- The True "Tri-Edge" - An AIDA-PC infected by "AIDA<Tri-Edge>", the first of the AIDA to become aggressive and attack a human. This aggressiveness quickly spread to the rest of the AIDA. He is known among players for the three-edged Sign he leaves.
- AIDA<Tri-Edge> (PC) the original AIDA that started it all taken PC form.