Its the old hard or extreme trials bumped up to 80. they have said this numerous times

Hell the reason its OG shiva is because it was originally going to be titan, but they considered Titan hard/extreme to be too difficult as it was on par with a savage level fight at release both times (though as its synced to 80 i doubt it would be on account of absurdly good healing kits now which was part of OG titan's difficulty- you had to beat him before the scaling tumult damage started out pacing the healers healing power)
I find that a bit insulting tbh, everybody did titan hard because it was the last step in the first stage of your relic and yes, it was challenging, but that was more due to server ticks and very little gear creep available

there was no need to go straight from the hardest to the easiest primal at 50! Should give it to ifrit as he was the first primal and middling in terms of difficulty.