Alliances within the Trial of Champions, alas, cannot last until the end...
Other References to ThromEdit
A "notorious axe-wielding barbarian" called Throm was believed to have buried a treasure hoard somewhere on the Pagan Plains. He was rumoured to have died in Deathtrap Dungeon before the events of The Port of Peril, which appear to have occurred before the Trial of Champions was defeated for the first time, suggesting that this is not the same axe-wielding barbarian who accompanied the Hero of Deathtrap Dungeon. Indeed, the term "notorious" does not seem to fit the seemingly honourable barbarian described above and the wording of his introduction to the future Champion of the Labyrinth ("Throm, as your barbarian ally calls himself") may indicate that the hero was aware of another, more famous (or infamous) Throm.
This hypothesis seems to be confirmed by Deathtrap Dungeon: The Last Champion, a Fighting Fantasy Audio Drama narrating an earlier edition of the Trial of Champions, where a participating barbarian called himself Throm explains to Vale Moonwing that Throm is a name that the members of his tribe took when they enter adulthood, until they found their true purpose, and their true name, by adventuring. Vale herself confirms that she has already met another warrior named Throm in the past. 
Further Information in CanonEdit
More information can be found at:Source
Deathtrap Dungeon (paraBackground pg24*, pg25, para22, para23, para41, para63, para73, para105, para126, para149, para154, para184, para282*, para288, para299*, pa ra302#, para311, para388)