The Cobolt Cave systems is full of...well...Cobolt. But there are also seams of Labrynne Midnight, a blue gemstone with weird properties. It gets used in some puzzles down there.
I'd really like to get rid of LockeZ. His play style is way too unpredictable. He's always like this too. If he ran a country, he'd just kill and imprison people at random until crime stopped.