Entei

Entei can make even the mightiest physical attackers cower in fear of Sacred Fire, if that is what you wish. Sacred Fire is the main selling point of Entei, as it deals good damage to most Pokemon that don't resist it and has a 50% chance to burn the target. Since it is not a contact move, it also avoids the Attack drop from King's Shield, which can make Entei a decent check to Aegislash. In addition to this, it doesn't have to worry about Rocky Helmet, unlike other physical attackers. Entei provides a check against many dangerous Pokemon in Battle Spot Singles, such as Volcarona, Rotom-H, Mega Charizard Y, Thundurus, Gengar, and Aegislash. Its lack of a Fighting-type weakness differentiates it from Heatran and complements its overall bulk, and Base 100 Speed allows it to outspeed Pokemon such as Breloom and Heracross with little investment.

Entei's downsides are its incredibly shallow movepool and inability to deal with bulky Water- and Ground-types. The loss of Extreme Speed and Flare Blitz in the Battle Spot Singles metagame limits its movepool further and makes it very predictable. It is weak to many common Pokemon in the metagame, such as Garchomp, Kangaskhan, Landorus-T, and Suicune. However, many of these threats cannot safely switch into Sacred Fire.