Lokis attack is similar to Enels or Kaidos top elemental attacks. Can't remember if Big Mom might have had something similar, probably lesser scale.
Kizaru does not have this AP/AoE, Akainu most likely does. Ace attacks were mostly on a lesser scale except his final attack, Sabo yet to show.
Hakai is an entirely different kind of attack. That is pure haki. No fire, lightning, magma but just straight up destruction. Much more similar to Xebec, Shanks, Roger or Mihawks types of slices/cannons of compressed haki force.
Writing all that: It's mad how powerful Enels attacks were all the way back in what, chapter 250 give or take. He had the power to wipe out entire islands and his CoO is still top 5 in the series. If he learned any decent haki in the moon and comes back with an army of Automatas dude is legit a 3-4B threat.