Bug team?

Just about any team could be viable if you make it work.

And even though they are generally bad, there are some very good bug type Pokémon: Scizor, Yanmega, Volcarona, Heracross, and maybe Scyther.
There's also Shuckle and Forretress for defense...

Your biggest problem will be Rock and Fire type attacks. And of course also Flying, but they aren't nearly as common.

 

You can easily put together a mono-type team. They're great fun to make, and a lot of them can be somewhat viable in competitive play.

The only drawback if you use them very competitively is the same weakness that your team will likely have. My Mono-rock team does really great, but it will 100% lose guaranteed to any team with Bullet Punch.

If you want some help making a Bug-team, let me know! I will be happy to help.

 

Your biggest bets would be the bug-steel types like Scizor, Forretress, Wormadam-Trash, Durant, Escavalier, and Genesect, granted you arm yourself to eliminate fire-types. Ground-types would be good to take care of, too. Genesect's Techno Blast is a great way to give yourself coverage with the special drives.

 

A bug team wouldn't be very viable in competitive OU, but it can be against other monotype teams. Like some other members mentioned, Scizor, Genesect, Volcarona are great for an offensive based team. Forretress is helpful for eliminating entry hazards (especially Stealth Rocks) so that bug Pokémon can easily switch in and out of the battlefield. Utilizing the bug move uturn is especially important and helpful if you have a support Pokémon like forretress; forretress can set up entry hazards and a bug Pokémon with uturn can switch to a Pokémon that has an advantage over the opponent's, forcing a switch.

A weakness to a monobug team is ghost type Pokémon. They resist bug type moves and they prevent Forretress from using rapid spin. Even though this problem exists, people can work their way around it. Scizor can use pursuit to eliminate ghost type Pokémon; however, will-o-wisp poses a great risk on the functions of Scizor and it is very important that one does not let their scizor get the burned status.

 

What about Ninjask? With the ability that boost it speed, batton pass, sword dance, protect/substitute and x-scissors is a great Pokémon to charge speed and attack and then use batton pass to have ready another Pokémon (for bug types, we can consider Escavalier. Its low speed is not a problem thanks to Ninjask). Ninjask is also speeder than Deoxis-S after turn 1.
I also want a bug team Maybe when we both have it we could fight

 

Ninjask used to be great, but now it is an easy Pokémon to defeat. Like you mentioned, it's perks are baton pass, swords dance and speed boost ability; however, many Pokémon can counter that with moves like taunt (with prankster), roar, whirlwind, and priority moves. An experienced battler can easily dismantle a team that relies on Ninjask, so if you aren't planning on using a Ninjask competitively, then it's okay (i guess).

 

However I want to try it xD
But thanks for your comment, is important to know how people can count my Pokémon to avoid that xD

 

It kind of depends on your meaning of the bug Pokémon. Y'know what i mean? No? You could use them as Offensive Such as Genesect. Using Rock polish with its AMAZING SpA. You have a really good sweeper. Or you could just have a Volcorona, and be bulky user, Then survive a couple hits, while quiver dancin' it up. You're almost unstoppable after 2 Quiver dances. And So forth.

 

Or you can make an offensive Forretres. No one'll spect that, and it has powerful moves such as earthquacke, gyro ball or explosion.