Level 34.5 Gyarados: B/DP (Max IV)
Level 34.5 Rhydon: MS/SE (14 Attack IV)
Level 30.5 Dragonite: DB/DC (Maximum attack IV)
Level 30 Vaporeon: WG/HP (Max attack IV)
Level 30 Vaporeon: WG/AT (Max attack IV)
Level 30 Vaporeon: WG/WP (14 Attack IV)
Level 30 Gyarados: B/HP (14 attack IV)
Level 30 Machamp: KC/CC (13 Attack IV)
The rest is probably worse
3k Blissey? Dragonite's gauranteed to win if you dodge DG (if it has that) Machamp with Counter should win, Gyarados with B/HP, imagine Rhydon should as well.
Why not try it out? Most of these should win with optimal movesets but the Vapes might struggle a bit depending on secondary moves.
Blissey isn't impossible to beat, high IV optimal moveset attackers should not have too much of an issue if you dodge the DG / HP
Your list is excelent for the future. The OP listed his pokes as he had them from before the update.
From your list Dragonite can or will after you take it to 33.5. I did a 2959 one with pound hyper beam. I got beaten by mune 3954 zh/ dg of mine but I missed some dodged.
Vapes will time out for sure, verifien agains mine with 34.5 lvl hp vape.
Keep in mind I'm talking about 34.5 lvl blissey, even 1 lvl lower, so in hight 2800 or low 2900 things can be better for vapes.
Advice for old mons: try starting with a gengar, then after he uses hid charge moves 1 or twice swap for strnger but slower mon.
I just looked at gengar I used, it was sucker punch with dark pulse :). But I used him in a different scenario: prestiging against a 2500 and something cp DG blissey. I did not start with him (1600 cp btw) but used him to finish the job after 1700 cp new matchamp with counter and close combat took like 75 % of blissey's health. And he ussualy survived to take like 20% of the Snorlax that followed in gym.
So I'm sugesting Gengar only to take more of blisseys health compared to the length of his life, like 40% during 25 seconds (random values, not experimented ones).
