Since I posted an in-depth message about Entei in the Entei thread, I decided to post it here as well because it was quite some work typing it and it fits well here. I feel like Entei being ranked B is pretty solid, but overall its a "B+" in my opinion because Sacred Fire gives it B status already IMO but other factors along with Sacred Fire this gen makes it a B+ rank. Explanation below:
While Sacred Fire is the core reason why Entei has had a sudden surge in viability, that isn't the sole reason. There are a few factors in this generational step that has made some changes to using Entei. After a tremendous amount of games both on Wifi against many players including skilled uploaders on youtube and on ladder on Showdown I have come up with a these findings that has made Entei much better this gen:
[1] - The incredible buff to Defog. Entei loves support / walls with Defog such as Mandibuzz (which I've been testing with Entei). The ability to wall many physical threats, taunt hazard setters and easily defog all hazards is amazing. Being stealth rock weak and prone to both spikes and sticky web is a huge problem, but this gens defog and Mandibuzz makes it so sweet for this Volcanic Beast.
[2] - The addition of the Sticky Web hazard. While this effects Entei as well, if you are running him you should have a good rapid spinner or preferebly a defogger in your team and get rid of the opponents hazards and learn how to set yours after. Unless they have both a defogger and a setter like you which is rare they will usually lose out on the hazard battle, as I've found it easy to take out their rapid spinners. Having Sticky Web out on the field this gen greatly helps Entei's above average speed to great levels, outspeeding Infernape, Garchomp, Terrakion, Keldeo, etc which suddenly can't switch into your Sacred Fires anymore as not only did they already risk being burned, but now get outsped and KOed by Sacred Fire. Overall if you manage to have stealth rock or just sticky web support along with a good defogger to help entei with stealth rock, spikes, and opposing sticky web you will realise just how much powerful this guy is.
[3] - The extremely high usage of Aegislash, Talonflame, and Mega Lucario. Entei actually checks these in three different ways that you wouldn't expect but that I've found over many games. Aegislash is the easy one - there's almost nothing it can do and your sacred fire is not only OHKO but it doesn't make contact rendering King's Shield useless stall against Entei. Talonflame is a commong switch in but fails to OHKO and gets 2HKOed by sacred fire (once on the switch and second time after brave bird) so you don't even need to predict the switch into stone edge, which enables you to keep spamming Sacred Fire after without being locked into Stone Edge. All other situations Talonflame loses to either a Stone Edge after failing to OHKO Entei or loses to Extreme Speed. Finally, Mega Lucario's adaptability close combat has a measily 30% chance to OHKO with close combat against an Entei with completely no defense / bulk investment. With some investment which is completely doable because of the forced adamant nature, it almost never OHKOs and gets OHKOed back by Sacred Fire, so I've realised many of my opponents who have had this experience actually switch out when Entei is facing their mega Lucario.
The Numbers showing failure to OHKO:
252 Atk Adaptability Mega Lucario Close Combat vs. 4 HP / 0 Def Entei: 170-202 (89 - 105.7%) -- 31.3% chance to OHKO
252+ Atk Choice Band Talonflame Brave Bird vs. 4 HP / 0 Def Entei: 142-168 (74.3 - 87.9%) -- guaranteed 2HKO
252+ Atk Talonflame Brave Bird vs. 4 HP / 0 Def Entei: 94-112 (49.2 - 58.6%) -- 98.8% chance to 2HKO (with leftovers running perhaps Sword Dance)
[4] - Great options to allow Entei to enter the field. Volt-Turn Cores are a great idea to allow Entei to enter, and this gen there are some really powerful options that weren't present before. I've been having amazing success with Genesect, Mega Manetric, and even Noivern. The first two are definitely the two best new additions but Noivern's speed and niche lets it fit well if you know how to utilize it's strengths. You have the ever prominent Rotom-W just as strong this gen to help with slow Volt Switches as well. The point is you don't need to force half-viable volt-turn pokes onto your team for the nice entries with Entei, he has great powerful options that not only provide volt-turn but their own strengths. Genesect is a powerful attacker and cleaner that has it's only weakness covered by Entei, allowing to u-turn out of fire moves into safe entrance of Entei and Mega Manetric is a decent attacker that is amazing with Intimidating and Volt Switching out into a safe entrance of Entei especially if that poke is physical and just got intimidated.
[5] - Finally, we talk about Sacred Fire. As mentioned, this the core reason why Entei has more viability, but the reason's are more than what meets the eye. Sacred Fire on paper is already deadly enough, IMO one of the best moves in the game being 100BP almost max accuracy and packing a whopping 50% chance to burn. Backed by stab and choice band coming off 115 positive natured attack and you have a absolutely devastating ability that burns half the time. Incredible. It's good to send Entei in to deal with pokes vulnerable to Sacred Fire, this forces switches which we want when using the beast. This threatens switch ins to get hit hard even if resisted and spreads burns to the enemies teams. If played well, you will often cause several burns that cripple physical attackers / walls and wear down special attackers / walls.This not only puts pressure on the enemy team to ponder whether to make the switch in in the first place, e.g. switch in Terrakion, Tyranitar, Garchomp etc risking the burn. So against those that are neutral or weak to Sacred Fire Entei wrecks, and for those switch ins or checks the burn and sheer power behind the attack is still so damn difficult to deal with immediately making Entei a threat to any team.
Aside from burning, hitting hard and forcing switches, Entei while lacking great coverage, has a hard-hitting Stone Edge to deal with common switch ins and even flying types, and Extreme Speed is great for many situations with all the priority floating around in the tier (especially that damn brave bird). I do prefer Bulldoze as the last option to hit heatran, and if you predict wrong the 100% chance to lower speed is always beneficial to your team thereafter. All in all I'm pretty happy with the results I've been getting with Entei this gen, there's so much more to him now then there was before.
