Alright, this is my last try to convince you guys. I tried my best, and have tried to stay realistic enough. ;p
Now, what if we took a Speed-twinked Orlandu (no status blockers), and Cray speed boosted him? This would put him at over 2.5x speed, easily enough to lap Ness' below average speed. Orlandu would let off an initial Holy Explosion (I mathed out at about 0.92 PCHP, with speed-twinked equips, surprisingly). Now, much to my bewilderment, Me First goes into effect even before the attack is executed, which is retarded, it assumes that Lucario can predict whatever attack Orlandu's going to pull off. I mean, does anyone share my bafflement about this? If Lucario uses Me First, it has to be used on someone before they act, but they haven't actually chosen what they're going to do until after Lucario's acted. I mean, if he used Me First, and executed the attack only AT THE POINT where the person he used it on proceeded to act, I'd comprehend that, but... <.<
Alas, I'll roll with it. So, instead of unleashing a second Holy Explosion, what about a Night Sword? It's much weaker than a Holy Explosion, and has parasitic healing attached to it anyways (Orlandu -arguably- survives, and if he does, it's just barely. He could even lower a few points in PA, to ensure he survives his own Night Sword. In advance, I'm aware that Me First is 1.5x damage). However, either way, going for Me First on Orlandu means that Garnet's open to summon (her most powerful of which hovers around ~0.5 PCHP, and if she goes for an elemental one, the Pokemon are gonna be hurting, too). With that kind of damage on him, either Chemist or Adray can potentially kill Ness off. Charizard's still got an attack, but he's either finishing off Orlandu (who may have very well lapped him, Orlandu's speed is MONSTROUS at this point), or hurting Chemist/Adray. Not both. We'll say Chemist gets put to sleep (and those odds aren't even 100%, I'll remind you), and Adray finishes the job with a combo. The other way around, Chemist can use a Succubus Kiss (its damage is actually not that horrible, it's around 0.3 PCHP, not to mention, he can heal himself from some of the damage that Blastoise/Charizard may have caused). Ness is almost exactly equal to 1.7 PCHP. Those three blows oughta be enough to take Ness out!
It's now the four Pokemons against my team, 'cept Orlandu might be dead, but even so, I have three revivers on the job, two of which have either not been touched, or remain in healthy condition. I can manage! I'm in no way saying I win this fight easily, but I can pull through it alive.
EDIT: Keep in mind, Ness has below average defense, despite that insane HP score. Holy Explosion, the summon and Adray's Combo may well do a little more than I put them as.