He previously held the title "The Dark Champion", but since the second official trailer, he now holds the title "The Barbarian King".
In the August 31st 2010 edition of The Journal of Justice, it was written that Tryndamere was passed down his sword from his father, who had it passed down from his father before him, and so on. Tryndamere said his father's words of wisdom were "master using it and you can have this" - a quote from the original Legend of Zelda on the Nintendo Entertainment System, released in 1987.
His story appears to have been based off of the opening sequence of the 1982 "Conan the Barbarian" movie, in which Conan's entire village is slaughtered and he swears revenge upon those who destroyed it.
In the original stories, Conan is said to have come from a nomadic people of the far north of his world, while Tryndamere comes from the Northern Freljord.
Conan is said to have "become a king by his own hand" in the 1982 movie. Tryndamere became the Barbarian King by uniting all the Barbarians of his home land under his leadership, thanks to his friendships with most of the Barbarian leaders.
Tryndamere's dance refers to Hopak, the traditional Cossack dance. His previous dance, before patch V184.108.40.206, was a reference from N'Sync's dance in their song, Bye Bye Bye. A side-by-side comparison can be seen here.
As of patch V220.127.116.11, Tryndamere now uses the Fury system instead of health for his abilities.
The Demonblade Tryndamere trailer can be seen here.
This skin is possibly a reference to Nightmare from the Soul Calibur series of games.
This skin also bears a resemblance to Haru Glory from the Rave Master series. one of Haru's swords will claim the soul of the wielder in exchange for greatly increased strength. During the process, the sword will fuse with the wielder's arm.