My first (and only) Defender on Live was a Dark/Elec with the concept of being a Blastroller. It had pets with Voltaic Sentinel and Dark Servant, multiple single target holds to lock down bosses, end drain to lock out minions, and actual blasts for damage.
Unfortunately after Enhancement Diversification you couldn't end drain, your holds didn't last, your damage was pitiful, and they also changed pets so you couldn't summon multiples even with enough recharge.
I didn't get him to 50 until after IO sets were a thing and it was still a slog becauce my guy never got to do what he was meant to do =(