Raze is a General in the Black Ring and in charge of Raze's Flying Fortress in the Orobas Fjords. The entrance is on an outcropping on a cliff facing Champion Harbour. His fortress is surrounded by lava, but when you meet him, he complains that it's much too cold for him. None of the responses have any impact on the coming fight, so choose one that feels right to you. You can mindread him to learn: "These Boots of Ulthring are not warm enough. I need new ones!" This causes him to drop Ulthring's Leggings from the Ulthring armor set when he finally keels over.
This battle *should* be fairly easy, only it can become frustrating very quickly. When you get Raze down to 50% health he will quickly try to run to one of two healing booths. A short cutscene follows that prevents you from taking any action, and Raze will respawn between these booths with 100% health. Two other booths also constantly spawn Walking Armors, but these are more of a nuisance, as they can interfere in your battle with Raze.
The solution appears to be switching these healing booths off, however this only lasts 15 seconds. You have to be able to take down a level 30 boss within 15 seconds from deactivating the booths. There is no point camping these booths as you can't be two places at once. Camp one of them and he simply heads to the other. You can hope to draw Raze to a booth you deactivated in the hope that he will have longer to run to the one that is active. But this will be a long fight as his healing booths are limitless in capacity.
You may find it quite simple if you deactivate one when he is at about half health then when he runs to the active booth, deactivate that one and go camp the other. Alternately, spawning your creature and summoning as many friends as possible (Summon Demon, Summon Ghost, Summon Undead), together with the Walking Armors can create enough congestion to prevent Raze from escaping quickly enough to heal himself. If you have the Rush Attack skill it can quickly close the gap as he's running away. Whirlwind's ability to knock down an opponent may also prove useful. What little is written in various forums and FAQs seem to suggest this fight will come down mostly to luck.