OK, first off, sorry I took so long to respond to this, but classes will have that effect, not to mention this Arceusdamn cold I got. >_< Anyway...
1: Sylveon and Slurpuff are far from useless. Pixilate Sylveon's Hyper Voice surpasses Moonblast's power and hits through Substitutes, all off of an amazing base 110 Special Attack. And Slurpuff sets up with Calm Mind, attains incredible Speed courtesy of Unburden, and if it can at least get in two Calm Minds before the Sitrus Berry activates and Unburden kicks in (not a difficult feat, considering Slurpuff's respectable bulk), that's the equivalent of a f***ing Geomancy right there. Oh, and Dazzling Gleam, Surf, and Flamethrower, they hit everything for neutral damage except Tentacruel and Qwilfish. That's some damn good coverage right there. Slurpuff is practically my signature Pokémon when I battle over wifi, and let me tell you, she gets results. You're just calling them useless because they're useless for your side of the argument, because they're good Fairy-types that Dragalge can beat.
2: Klefki f***s just about anything up badly with enough luck on its side, so saying that it f***s Dragalge up badly does nothing to aid your argument.
3: You got me on Gardevoir and Azumarill surviving Sludge Wave, but only for now. Once Adaptability comes out, have a look at these damage calcs;
252+ SpA Adaptability Dragalge Sludge Wave vs. 252 HP / 4 SpD Azumarill: 448-528 (110.8 - 130.6%) -- guaranteed OHKO
252+ SpA Adaptability Dragalge Sludge Wave vs. 4 HP / 0 SpD Mega Gardevoir: 288-340 (103.5 - 122.3%) -- guaranteed OHKO
So yeah, just how are they gonna switch in on Dragalge once Adaptability is available for it, hmm? I've said it before and I'll say it again; Dat Sludge Wave.
4: You think maybe you can ease up on calling it "Dragawful" or any variation thereof?
Gardevoir will always survive Sludge Wave, remember what I said? She outspeeds and sets up Calm Mind. Lets look at the calculation now, accounting for Calm Mind.
252+ SpA Adaptability Dragalge Sludge Wave vs. +1 4 HP / 0 SpD Gardevoir: 224-264 (80.5 - 94.9%) -- guaranteed 2HKO
And that's just the base form Gardevoir that nobody uses, not even the Mega version. Face it Dragarbage is a chump, and Adaptability isn't going to change that.
Klefki doesn't need luck to beat Dragawful, since there's next to nothing Dragaloser can do in against him. Klefki is immune to Pulse and Sludge Wave and +2 Foul Play deals more damage to Dragarbage than Scald does to Klefki, and that's not even taking the backfire from confusion into account.
Azumarill would die to a single Sludge Wave once Adaptability is out, but all that really says is Dragalge can OHKO a single mediocre OU Fairy Pokemon under the right conditions and at the cost of most of its HP, since it would still be outsped. That's hardly an accomplishment, Arbok could boast the same, are you going to argue that Arbok is great too? It's better than Dragawful, I'll tell you that.
252 Atk Arbok Gunk Shot vs. 4 HP / 0 Def Gardevoir: 420-494 (151 - 177.6%) -- guaranteed OHKO
Zangoose is the one good Pokemon that came after Gen 1, everything else about Gen 3, as well as gens 2, 4, 5 and 6 is awful. I do not like Gen 3, just Zangoose.
To be fair, whenever Adaptability Dragalge comes out, its dragon and poison attacks will be one of the strongest in the game. Its Draco Meteor will reach the level of Turboblaze Reshiram's in terms of power.