Strongest class/job lore wise?

[Shippuu]

Well if we're just going to talk pure potency (which is mixing gameplay with lore, which doesn't really connect usually in that way) then Dark Knights would be up there as well with some 400 potency attacks (or more) that can even heal themselves by doing them

WAR still has them beat. They have Dark Arts Souleater at 400 potency 100% heal. Then Dark Arts Carve and Spit at 450 potency. Warriors Inner Beast is only 300 potency, but with Berserk, 50% more would be 450 potency with 100% heal. Still doesn't come close to the Berserk Fell Cleave with berserk. 500 + 50% = 750.