I disagree challenge rating here or there. Its not possible to make a paladin Freaking boss that is an avatar of a God at lvl 11. To have 0 spells 0 lay on hands. Its lazy the design is lazy. I think this status is even higher then a legendary enemy. I agree that hp pool can be random its totally possible to end up in dnd with 28 hp as a lvl 12 wizard with zero con. But I gently push back cuz it's almost impossible to have with 14 constitution as a lvl 12 Rouge to have 28 hp you literally need to roll 12 times 1. What you say is not possible and it's. Bull shit.
Also if hp pool is random it should be random. Also the enemy should have spells abilitys. Its not possible to have high challenge rating and getting 700 XP /lvl 12 enemys that have 28 hp . Also it's not possible to get 700 XP from a lvl 3 intellect devouler and when you are ion the ship the beginning of the game you are facing the same lvl intellect devouler and killing it rewards you for 5 experience . And Grym is not legendary. It's a side mission boss. Its optional same as the lava elemental.