Fields of Hatred (PVP event)
Now wether you like PVP or not, the PVP area offers one of the most viable way to farm legendary equip.
Purify Seeds of Hatred at an Altar of Extraction to turn them into Red Dust
There are a lot of monsters there, even PVP Boss, which you can farm for Seed of Hatred (or even regular gear, since density is pretty good). Seed of Hatred is a currency which, once converted via the PVP altars, allows you to gamble for gear (also offers a few cosmetics).
It was the most viable way to farm gear, and so most players didn't Bloodmark (pvp flag) themselves so they could cooperate and simply PVE farm.
Bloodmarking oneself allows you to attack anyone (including non-Bloodmarked players), it's basically "hostile mode", and doing so increases your Seed of Hatred rate, but you can choose not to Bloodmark yourself and cooperate with other non-Bloodmarked players to simply farm PVE monsters. This will not prevent you from being attacked by hostile "Bloodmarked" players though.
- Extremely variable depending on the hostile Bloodmarked players present. PVE monsters themselves are moderately challenging (easy with a half decent build). The roaming boss Khazra Abomination can be challenging and depending on your class/build, may not be soloed. Playing in group is more efficient and will give you a significant advantage.
- Seeds of Hatred (allows you to gamble gear and buy a few cosmetics, can't be gotten anywhere else).
- Monsters also drop regular gear, including legendary. Density is pretty good.