Simply put, the worst Dragon in the game. It's got a terrible cost:attack ratio, is incredibly expensive, and only has one good point, it's hp, which really doesn't do much to make up for the lost attack and high cost. Once you're past 15 hp, having 30 or 1000 really won't make a difference (Except in the case of Gravity Pull).
Some players may argue that it's a good card because you can put it+Grav Pull in a deck and use it for both offensive and defensive options, but tell me this, would you rather have one Charger and one Armagio (10
total cost, 11 if you use Gravity Pull, and 9 damage with 7 of it having Momentum.) or that Dragon+Grav Pull? It's more quanta, less damage, none of it has Momentum, the same hp-soaking (Except if you use it on the Dragon your offense is gone, while option 2 will still leave you the Charger) potential, more vulnerability to Freeze+Shockwave/Rewind/Mutation, and the simple positive trade-off is that you can harness Grav Pull for CC, but not many creatures are a threat to an 8/30 Dragon (Otys and Scarabs just cry) outside of Arctic Squid and Fallen Elf/Druid.
So, I propose that it gain Momentum upon play (Like Phase Dragon except that it's a beefed up Charger instead of an Immortal), at least one extra attack, both of those, a cost reduction, or, last, that the "Catapult" card Zanz mentioned works better with high-hp creatures (Perhaps something like direct damage equal to hp/2? Titans would be fine because it's a 3 card combo for 35 damage, and Unstable Gas easily surpasses that).