Using a Bisharpite, a Bisharp can further evolve into Mega Bisharp. Its Mega ability, Moxie, allows Bisharp to increase its attack every time it knocks out an enemy Pokémon. Furthermore, Mega evolving Bishop will lead to a +35 boost in the attack base stat, a +10 boost in the defense base stat, a +5 boost in the special defense base stat, and a +50 boost in the speed base stat.
At first glance the stats of Mega Bisharp aren't too terrifying by Mega Evolution standards. In fact, with a Life Orb regular Bisharp does quite a bit more damage then its Mega Evolution. Mega Bisharp would much rather have a defensive boost over a speed boost since its main attacking move, Sucker Punch, has priority anyways. So then why is Mega Bisharp considered so dangerous? The answer lies in the ability Moxie. Mega Bisharp is easily able to come in and finish off a threat with Sucker Punch, earn a Moxie boost, and then basically breeze past entire teams, gaining an attack boost after each successive kill. It can even switch into a Defog before Mega-evolving, nabbing the Defiant boost and preferably the Moxie boost as well, turning it into a sweeping machine capable of dismantling teams in an instant.
The best counter used to be Skarmory as it could take a Brick Break easily and resisted Mega Bisharp's moves that receive same-type attack bonuses, but now that Steel no longer resists Dark in Generation 6, which Insurgence uses the mechanics of, Mega Bisharp can easily dispatch of it with a boosted Knock Off. The player's best bet is to use Scarfed Fighting-types or those with Mach Punch/Vacuum Wave, such as Conkeldurr or Lucario. That, or other powerful revenge killers. With the buffs its regular forme received in the new generation, Mega Bisharp is a terrifying foe indeed.