After spending the last decade being completely outclassed, first by its fellow legendary beasts and later by Arcanine, Entei has finally found a home in RU. With most of its rivals safely locked away in higher tiers, Entei is free to rampage through RU unhindered. Its high Attack and Speed stats and access to Flare Blitz and ExtremeSpeed make Entei easily one of the best physical attackers in the tier, but it can also use Calm Mind to become one of RU's most dangerous (and overlooked) special sweepers. Its movepool is quite shallow, and the forced Adamant nature that comes with its event moves hinders it to an extent, but do not overlook Entei; its power and versatility make it a Pokemon every successful team must consider.
Entei's combination of power, Speed, bulk, access to ExtremeSpeed, and immunity to Will-O-Wisp makes it one of RU's most fearsome physical attackers. With a Choice Band equipped, Flare Blitz 2HKOes everything that doesn't resist it, while ExtremeSpeed takes a huge chunk out of most offensive Pokemon. Together, these two moves make Entei both a powerful wallbreaker and an excellent revenge killer. In the third slot, Stone Edge OHKOes Aerodactyl, Moltres, and most relevant Fire-types. Unfortunately, Entei's physical movepool essentially ends there, so the final slot is largely filler. Hidden Power Grass may seem out of place on a Choice Band set, but it allows Entei to 2HKO a few Pokemon that would otherwise force it out, such as Kabutops, Omastar, Quagsire, and Rhydon. Sleep Talk is a useful option for handling sleep inducers, as Entei can switch into almost all of them including Smeargle, Lilligant, Tangrowth, and Amoonguss.Team Options & Additional Comments >>>
With base 100 Speed and the ability to create 101 HP Substitutes, Entei is an excellent bulky Calm Mind sweeper. Although Entei's average Special Attack and limited special movepool prevent this set from being as immediately threatening as its physical set, it is surprisingly easy to set up. Entei's reputation as a powerful physical attacker makes it easy to force a switch and set up an initial Calm Mind or Substitute, and many of the best switch-ins to its physical sets, such as Kabutops and Poliwrath, are forced to switch right back out when they realize that Entei is running a special set. Entei's 101 HP Substitutes and high base Speed also allow it to set up on nearly any wall. If your opponent lacks the right counter or waits too long to switch it in, Entei quickly becomes unstoppable.
The first two moves are obvious, and Flamethrower is a pretty clear choice as well; its 100% accuracy means that Entei doesn't have to worry about losing its Substitute due to an untimely miss, and it has plenty of power once Entei has set up. Lava Plume can be used over Flamethrower for its high chance to burn the opponent. Hidden Power Grass is usually the best option in the last slot to cover Pokemon such as Kabutops, Quagsire, and Rhydon. However, Roar is also a viable option, especially with entry hazard support. Phazing is one of the only ways for opponents to stop Entei once it sets up, but Entei outspeeds every common phazer and can Roar them out first, forcing them to take another round of hazard damage and giving itself another turn to set up. Roar also prevents Pokemon such as Calm Mind Slowking and Calm Mind Uxie from setting up alongside Entei. However, sacrificing Hidden Power Grass means most Water-types will completely wall Entei, and Roar's negative priority means they will always be able to hit Entei with Surf or Waterfall before it can phaze them out, so Entei will need its teammates to eliminate the opponent's Water-types before it attempts to sweep.Team Options & Additional Comments >>>
Physical Entei can forgo a boosting item and use Leftovers instead to take advantage of its natural bulk and avoid being worn down by residual damage. This opens up some new options for that otherwise forgettable fourth moveslot, most notably Will-O-Wisp. Using Leftovers reduces Entei's potency as a wallbreaker and revenge killer, but it still has respectable power even without a boosting item, and the ability to stick around longer and cripple certain counters with a burn is sometimes worth the power drop.
Entei can use a mono-attacking set with RestTalk, Lava Plume, and Calm Mind to keep itself healthy and potentially set up multiple boosts (especially with a few lucky burns). Such a set is very threatening to stall teams, but it is also an invitation for Omastar to come in, set up a Shell Smash, and sweep your team. You can try a more defensive RestTalk set with Roar in place of Calm Mind to spread burns and rack up entry hazard damage, or even a full support set with Will-O-Wisp and Reflect as well, but Entei's common weaknesses make it a poor wall in general.
An all-out offensive Calm Mind set with Fire Blast, Hidden Power Grass, and Stone Edge can surprise some of Entei's counters. Stone Edge may seem unorthodox on a Calm Mind set, but even without much Attack investment it does significant damage to Altaria and Moltres, which are normally good switch-ins to special Entei. Extrasensory is also an option for decent neutral coverage, although the only target it's really useful against is Qwilfish. Shadow Ball is the only other coverage move Entei has that's worth noting, but it offers absolutely no additional coverage over the options already mentioned.
Choice Scarf is a usable item on Entei, either as a physical attacker with Flare Blitz or a special attacker with Eruption. However, ExtremeSpeed makes Choice Scarf somewhat redundant for the physical attacker, and Eruption is generally used better by Typhlosion. Flame Charge is a decent option to boost Entei's Speed while retaining the ability to switch moves, and Entei's movepool is small enough that it won't mind only having three true attacking moves. Finally, Entei can use Howl to boost its already impressive Attack even higher; just note that Howl is an event move like Flare Blitz and ExtremeSpeed, meaning it forces Entei to run an Adamant nature, which makes it slower than many of the tier's top threats.
A Sunny Day set with Flare Blitz and SolarBeam can be used, as Flare Blitz will hit like a truck and SolarBeam will eliminate Water-types more effectively than Hidden Power Grass. However, SolarBeam will not be that strong, as Entei struggles to divide its EVs equally. Furthermore, a Sunny Day set is generally outclassed by Typhlosion who is faster and has higher Special Attack. ExtremeSpeed and Stone Edge are really the only advantages that Entei has over Typhlosion, but physical sun sweepers are rare so a Sunny Day set is usable.
Checks and Counters
Quagsire, Alomomola, Poliwrath, and Intimidate Qwilfish all counter physical sets quite effectively, but none of them enjoy taking boosted special attacks. Other Water-types such as Kabutops, Carracosta, and Omastar 4x resist Flare Blitz and also resist ExtremeSpeed, but neither of them enjoy taking a 4x super effective Hidden Power Grass; however, the former two can KO Entei with Aqua Jet before it has the chance to use Hidden Power Grass. Rock-types such as Rhydon can take on Entei, but they also fear Hidden Power Grass and dislike being crippled by Will-O-Wisp. A physically defensive Druddigon also takes Entei's attacks quite well and can cause damage with Rough Skin, but Druddigon distastes Will-O-Wisp. Calm Mind variants have trouble dealing significant damage to Moltres and Altaria, but they in turn cannot do much back to Entei, and they greatly dislike Stone Edge. Fast Pokemon with super effective STAB attacks, such as Aerodactyl and Archeops, can be troublesome for Entei, but physical sets can bypass this Speed difference with ExtremeSpeed, and special sets will often have a Substitute up to prevent revenge killing. Entry hazards are an effective way to weaken Entei, as it is weak to Stealth Rock and fully vulnerable to Spikes. The damage taken switching in will greatly reduce Entei's ability to set up, and Toxic Spikes will completely ruin any Calm Mind sets.
Entei receives Flash Fire from the Dream World, which will allow it to switch into Fire-type attacks for a free power boost and fire off a frighteningly powerful Flare Blitz. However, once Flash Fire is released, it will most likely be released without Flare Blitz and ExtremeSpeed, so it would have to use Pressure for physical sets.