I am I the only one not getting his sword after literally 18 times! I'm starting to think he doesnt even have the sword and none of my friends have it either. Plus, I want to collect all swords. So far, I got 5 out of 7 swords. But I'm not trying to whine or anything. I just wish they boost up the drops from bosses
With bosses, items may only drop once in 20-25 times. Each drop is random. You could get an item twice in a row or not for 100 tries.
There are swords in the Bazaar that also give a power pip and have 90 and 95 damage, which I believe is 5 less than the sword you want (Dean Darkflames Cleaver?).
Also, not too far from where you're at, when you finish "Forged in Fire" with Ashley at the Dragonspyre Academy, you get a Dragon Rider Staff (which is symbolically used for your Battle Drake). This is a Fire Staff with the same stats as Dean Darkflames Cleaver.