Escavalier, a new Bug/Steel type made for 5th gen. My sister named hers after a knight named Sir Ryasis from our local Renaissance Festival. Goofy nicknames aside, Escavalier has quite a bit going for it. It has a sick design resembling a Trojan helmet, a typing shared with only a few other Pokemon, and a fantastic Attack stat that can be further boosted with Swords Dance or a Choice Band. It's defenses are also great; base 70 HP is less than ideal, but base 105 in each defense is great and gels wonderfully with Escavalier's wonderful defensive typing. Unfortunately, there are some major things setting it back. As a sweeper, it is severely hindered by its sluggish Speed, although this can be remedied with Trick Room. As a defensive wall, it lacks reliable recovery. Nonetheless, Escavalier can make a great offensive/defensive Pokemon in the lower tiers. You can use it in OU too, but it is generally overshadowed by Scizor.
Swarm is the ability to go for. It boosts the power of Escavalier's Bug-type moves by 50% when its HP is at 1/3 or less. Escavalier is too slow to usually take advantage of this outside of Trick Room, but a Megahorn boosted by Swords Dance and Swarm behind that huge attack stat will be tearing holes in almost everything.
Shell Armor is an okay ability, but you can never know when its working because crits are so unpredictable. I suppose its some nice added insurance, however.
Overcoat is pretty useless. As a Steel type, Escavalier is already immune to Sandstorm, and Abomasnow isn't exactly the most common Pokemon out there. Even when it is there, Swarm is usually the better choice.
Escavalier's movepool is unfortunately very shallow, but it does get most of the tools it needs. You will always want Megahorn. It's Escavalier's strongest attack, and one of the things that sets it apart from Scizor. Its Megahorn is stronger than Technician Scizor's Bug Bite, and made even more terrifying by the possibility of Swarm and Swords Dance. You could go with X-Scissor if you prefer reliability, but you lose out on a lot of power. Without a Swarm boost, Escavalier's X-Scissor is weaker than Technician Scizor's Bug Bite.
You will also want Iron Head. Although Steel has horrendous supereffective coverage, it does get good neutral coverage, and Iron Head is one of the best physical Steel attacks out there.
Swords Dance is highly recommended for sweeping Escavalier. Due to its natural bulk, Escavalier usually can set up with ease on anything that lacks a Fire attack. For more defensive variants, you could go with Knock Off, as removing an opponent's item is always beneficial.
Pursuit is a great choice on this Pokemon. Many Pokemon, particularly Psychic types, will flee in fear at the possibility of Megahorn, and Pursuit will hit them hard.
Reversal is the only way Escavalier can really damage opposing Steel types. Although Reversal isn't a bad move, Escavalier is too slow to make good use of it outside of Trick Room.
Aerial Ace, Return, and Poison Jab are filler moves that could be used on a Choice Band set. Unfortunately, they have lackluster coverage at best, and pathetic coverage at worst.
Screech will force a lot a switches, and also works wonderfully with Pursuit. It also helps rack of damage from entry hazards.
If you use Escavalier in OU, keep in mind that it is not Scizor. Escavalier has a bit more base Attack than its fellow Bug/Steel, but it has a much shallower movepool, its horrendously slow, and it lacks priority. On the other hand, Escavalier's Megahorn is one of the strongest Bug attacks in the metagame. Also, its Special Defense is much higher, enabling it to always survive two successive Draco Meteors from Latios even after Stealth Rocks and if Latios scores max damage both times. It is also never 2HKO'd by Gengar's Focus Blast, always survives a LO Kingdra's Surf in rain, and can even survive Timid Magnezone's HP Fire 92% of the time. All of this data was taken from Smogon, and I don't believe it takes hax like stat drops and crits into account.
Partners: A Pokemon with Flash Fire is highly recommended, as Escavalier is a magnet for Fire attacks. Fellow UUs Arcanine and Chandelure are great choices. In OU, there aren't any Flash Fire Pokemon, but there are plenty of Pokemon with Fire resistances. Politoad is worth choosing, as its Drizzle reduces Escavalier's Fire type weakness. The frog Pokemon in general works great alongside Steel types. A Pokemon that can set up Trick Room is great, as it bypasses Escavalier's awful Speed.
Countering Escavalier: Fire attacks. Even with high defenses, any decent Fire attack will heavily damage if not outright OHKO Escavalier outside of rain. If your opponent has a Pokemon with Flash Fire, however, use caution. Will-O-Wisp also cripples it, as is the case with most physical attackers.
Finding a Pokemon that can actually switch into Escavalier, however, is very difficult. Almost nothing out there will want to take a Megahorn unless they resist it and have insanely high physical defense. Steelix is one such Pokemon, but it is RU. In UU, Chandelure is probably the best counter. It 4X resists Megahorn, resists Iron Head, and shakes off everything else except Pursuit. And it can easily OHKO Escavalier with its STAB Fire-type moves. In OU, Skarmory fills in that role best. It resists all of Escavalier's core moves and Roosts off the damage. It can't do much to Escavalier in return, and it'll hate loosing its Leftovers to Knock Off, but it can Whirlwind any Swords Dances the Bug has picked up. Heatran also walls Escavalier, and destroys it with Fire Blast. Magnezone can trap it and then KO with HP Fire, but Megahorn will hurt quite a bit.
Overall, despite its inferiority to Scizor, Escavalier can still be a deadly Pokemon. Its base Attack rivals that of Metagross, and its difficult to OHKO unless you use a Fire attack. And its design kicks ***. I think its a worthy addition to 5th gen competitive battling.