Yeah. If Fire Blast is used on the allout attacker then you really have no use for the Megahorn slash. Imho the set order of moves should be:
Fire Blast / Pursuit
With Megahorn in AC (or even OO) as an option over Fire Blast. I know it has an effective higher base power than Night Slash against Psychics, but you have to remember it's accuracy, and the fact that Night Slash has a 25% chance to crit. And even then, Sucker Punch is as powerful as Megahorn against Psychics. If you want to break Tangrowth then Fire Blast is the way to go. Other options that need to be ACd are Psycho Cut, as it 2HKOs incoming Qwilfish and Poliwrath who often come in on Absol, and Dread Plate should Absol be running Pursuit over Fire Blast. The extra survivability and bluffing ability have come in handy on more than one occasion for me. I think you should also mention that Fire Blast is very useful for Durant, as it often switches into Absol AND often tries to set up on it, meaning that Fire Blasting it as it sets up Hone Claws is generally a better idea than switching out. Don't mention Ice Beam in OO, as it doesn't hit anything, but rather Thunderbolt, as it' Absol's only way to 2HKO Alomomola. Speaking of which, that should also he in checks and counters, as even a +6 Night Slash fails to OHKO.
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