Bentley Berkeley makes a lot of claims, but this one was so ridiculous I had to actually test it. I set up an AE mission with an even-level Superfreak, a Freakshow Elite Boss. I hit it with Kinetic Melee's Assassin's Strike from Hide, with 100.8% damage enhancement, Build Up, Boost Up, 21.50% damage bonus from set bonuses, and the Superfreak having -30% res to Energy damage from its own resistances. All of that, on a very-high end build, was able to do 1/3rd of the Superfreak's health. So sure, these claims could be true, if you never actually fight anything, and instead exclusively Assassin's Strike from Hide and run away while it and Build Up are on cooldown.