Do the Pthumeru Chalice Dungeon - the first one. The ritual blood can be bought for 5,000 echoes (farm the executioners at Hemwick Charnel Lane, coming back from the Witch's Abode Lantern, you'll have enough if you kill two of them). The Chalice is relatively easy once you memorize the layout of it (any chalice that doesn't have ROOT in it's title is a pre-made dungeon), and the third/final boss of the dungeon has a guaranteed drop of a radial +10% Fire ATK UP gem. Spend another 5,000 from your winnings in the Chalice, obliterate it again, and then slot two radial fire gems into your weapon of choice. I was a full arcane build, and I literally could not beat those wolves/brainsuckers with my Logarius Wheel. Threw the two gems onto a Beast Cutter, though? 2-shotting the suckers (and crushing them to the ground before they could react) and keeping the wolves at bay. I need to go through the other Chalices to see what good farming I can get, but that first dungeon is AMAZING if you need radial fire gems (the second layer boss tends to drop somewhere around a 12% Physical ATK UP gem, too).