When jedi general Raven first saw the world of Katarr, he was overwhelmed by how much power was there. That made him to land on the surface. Here he find a child that had The Force flowning in his veins and a huge senzitive power.The Force was grater in this one, even grater the The Force of jedi Malak himself.
But he took the child on his ship dispite the protest of jei Malak.
Both jedi teaches the child on the ways of The Light Side and Jedi. But soon after the Mandalorian war, the Masters felt into the Dark Side and the kid has become his training in the Dark Side techniques.The child secret ability was to absorb Power from both masters and he becomed more powerful in a short time.
When Lord Revan killed Lord Malak (decived by the jedi council), the boy now a full grown man, was devasteted because his force sensitivity create a bound (a bound far greater then the bound between nihilus and Visas Marr or the Darth Treya and The Exile), when Malak died half of his contience transformed in pure Force energy.
After Nihilus consumed his world, from Katarr remains only 2 of them...he and a miraluka female Visas Marr,both were physically blinded and instead relied on Force Sight to see the physical world, which included the ability to see through walls.
Visas Marr
In time the Dark Force made him to kill his sister, when she was on Katarr (how Darth Treya predicted), after the death of Lord Nihilus.
One if many wickness is the much power he absorb the life of Lord Moxbestro is becomes shorter!
oh so you are calling me a little girl eh. I have no time to reply to childish immature insults such as said in the summary.