Let's start with what is a tank. In Pokemon, a tank is a Pokemon who can take hits and dish them back almost twice as hard. For the most part though these have almost always been physically oriented. Hence, Rhyperior and Swampert. Every passing month Rhyperior is on the rise. You want to know why? It can do amazing damage while taking hits like they are nothing. People have realized his potential. Colonel M and SoT can back me up on this. Well let's take an even deeper look at Rhyperior. Its a tank. It has a gigantic attack stat as well as amazing defenses. This attack stat allows Rhyperior to sweep but that is not the only factor involved. The defenses let him take a hit making his completely obsolete speed unneeded and not a factor. Rhyperior is literally a monster and a great wall, but it can almost always kill at least one Pokemon.
That is what I plan for this Pokemon except, it should be specially biased. Sure Scizor is on a rampage but so are Special Attackers. Most importantly lets look at Heatran, Zapdos, and Skymin. Assuming we are using the wished for Electric / Dragon typing, Zapdos can't really do shit. T-Bolt and Heatwave don't do anything thanks to typing resistances and non-super effective attacks. HP Ice is your only worry but it can only do about 1/4 to 1/3 damage as it is unSTAB'd. This is only using a 100 base SpD. That's one down. Heatran can only use Earth Power / Explosion. Explosion can't be helped but is uncommon nowadays. HP Ice is used a lot more and it is the same thing with Zapdos as mentioned earlier. Earth Power will do about 2/3 damage. Since you have an Electric-typing, T-Wave is a given. With T-Wave you incapacitate Heatran, and you rest off the damage, or you switch to another Pokemon who can now take over much more easily. That is two down! Skymin can almost OHKO, but almost, while you OHKO with T-Bolt. That's three out of three and that is just the tip of the iceberg! Think of what else we can do with this concept!
As far as abilities go, we can imitate a form of Solid Rock for this Pokemon, or we could just use Levitate and make Heatran obsolete. These are just some of the ideas, we can plan this whole Pokemon out together, or completely revamp these ideas! Abilities, moves, etc. are all up to you!
I'm not going to tell you why mine is better than any other as it may not be, that is fully opinionated and personal but I can tell what we can really do with "The Great Tank of China"!