Clan Chief Weyrloc Guld was the leader of the Krogan clan Weyrloc. Working with the Salarian Maelon Heplorn, Guld desired to cure the Krogan Genophage at any cost, and planned to conquer the galaxy with a new Krogan army once this was done. His desire to see the Genophage be cured at any cost was so extreme that he had absolutely no qualms experimenting on both humans and willing members of his own clan. Guld also believed that it was his destiny to conquer the galaxy, citing his having two children (a rarity given the Genophage) as a "divine sign", which most other Krogan were skeptical about.
In the end though all of Weyrloc Guld's delusions of grandeur proved to be for nought, as he and the rest of his clan were killed in battle against Commander Shepard and Mordin Solus during their attempt to rescue Maelon from the clan, not knowing at the time that Maelon was with them by choice.