Defiant: you automatically get a +25% DMG, and a +7.5% DMG & DMG Reduction per Rank of missing HP%. so if you have Defiant (5) and your HP went down to half, or 50%, you would be doing +37.5% DMG & DMG Reduction until you healed yourself, then the DMG goes back down towards the +25%. good for damage spikes. this is why many Builds have Masochism with Defiant, since it keeps the HP down at 50% most of the time, letting you have the better DMG from Defiant.
with Jasper Crystal, it is possible to have any MH Weapon for any Class to have Defiant. but if you look, half of them will have the +100% Elemental DMG, and the other half will have +200% Weapon DMG. for Wizard, Gauntlet & Wand has the ED and Staff & Sword have the WD. Warrior is Axe & Lance have ED and Sword & Hammer the WD. Rogue is Flintlock & Bow have ED and Chakram & Dagger have the WD.
if you are thinking of Ascending, eventually you will want Quest Myth Stones on all of your items to get the +200% Experience. you only need to farm floor 100-110, since monsters stop giving more Experience at floor 100. the only reason to go to higher floors is if you really need a certain item. killing monsters fast to get all the Perks is what is most important, and any room you have left over can be used for Luck and Gold Find for more loot, especially since you will be tweaking your Ascending Build to be better as you do your Ascending. I started with a bunch of Farming Legend Items, like the Adventurer Chest & Head, and just changed the affixes when I had the Crystals to do so.
Affixes & Myth Stones: using that Nadroji you mentioned, +2 All Sets is what most people want it for. you could put in a +2 All Sets Myth Stone for the +4 All Sets (this is the cap) on the same Nadroji. on other items, for instance, if you already had a +15% Attack Speed Myth Stone on an item, you wouldn’t be able to roll an Attack Speed affix on that same item, but if you had the +15% Epic affix or the +45% Attack Speed Crystal affix, you could still put the +15% Attack Speed Myth Stone on it. you would not be able to have an Epic and Crystal Attack Speed Affix on the same item.