[Nyara]

The fact is you don't need to counter Entei as he can't deal enough damage at all.

Way to counter Entei:

- Have RestTalk whatever
- Rest only with a Heal Beller later also works
- Don't be weak to Fire Blast

And that is... the most common set ever on GSC, so, yeah, unless you're facing a sort of hyper offensive team or a lame opponent, Entei is just helpess to do something at all, any other sort of team will have 2-5 walls ready to wall Entei to the hell and back, and to add problems, Rock Slide, Earthquake, and Surf are really common attacks from almost any Mixed Sweeper, and actually, really common on any good attacker, so, Entei don't even had a easy switch-in or can really win too much 1vs1.

Moltres BREAK walls from the moment almost all the physical walls are weak to Hidden Power Grass or Fire Blast, and the second best special wall of the game; Snorlax, can't wall it because it's 2HKOed under the sun by Fire Blast, but, yeah, Moltres is not that great, either, as it's walled by Tyranitar/Suicune/Vaporeon/Starmie, but teams offen just carry one of them, so, it's up to you to defeat them, and wreak havoc with Moltres later, but, yeah, Hidden Power Grass is still helping him to overcome them if spikes are on the field and they do have some previous damage. Entei by other hand is just hard-walled by anything not weak to SolarBeam+Fire Blast (or actually, he's even with SolarBeam walled by Tyranitar/Suicune/Vaporeon, anyway), and he's not a good wall. Well, there are other Pokémon who also wall Moltres/Entei, but most of them are BL's, too, and Blissey.

Entei's edge is he can check Starmie, but that is the unique thing that Entei is checking that Moltres doesn't (and it can just check it on few turns, Starmie can switch when Sunny Day ends, and she will win there), and well, Tyranitar without rest.