Very Fast, Infinite Multiple Respawn In Legacy Raid, Very Good XP (Patreon)

Sunwell Plateau (70-80) contains the mob "Sunblade Cabalist". This is an odd mob that periodically conjures its own minion, "Fire Fiend".

There appears to be no limit to how many fiends the Cabalist can summon. If you kill all the surrounding mobs and kite the ten or so Cabalists preceding the first boss to you, they will summon Fiends extremely fast. The Fiends award XP, roughly half of that of a world mob, and have only 22K health. They do almost no damage, players over 74 should not be affected by any amount of dps from them. 

This is a very fast XP grind, the fastest method I've come across apart from Method Zero, maybe even faster than that with an optimized set-up and class (so far I've only tested this on a fire mage, which is a poor choice for chain aoe casting). Although the instance is listed as being 70-80 it was still pretty good post 80. maybe viable till 82. (EDIT: xp seems to stop on reaching 81).

Killing the mobs can be quite easily automated. I had to do very little to kill them other than refresh fire shield. Players with minions should find it trivial. 

This will be a good option for lovely charm farming during the forthcoming "Love Is In The Air" Holiday. EDIT: forgot to mention mains have to be within 10 levels of mob to harvest charms, so 110's won't work with this.