If an electric type had wonder guard, and had air balloon with safe guard and rain dance, would it be invincible?
Yes, theoretically. You could get shut down by the move Gravity though, although it's never run.
You'd struggle to get it into the game though.
almost, but gastro acid, magic room, and gravity would stop you, and so will mold breaker/ teravolt/ turboblaze.
gastro acid and mold breaker/ teravolt/ turboblaze are very common