Dragonzord lay dormant in the sea off the coast of Angel Grove for an indeterminate number of years. After creating her evil Green Ranger, Rita Repulsa gave him the Dragon Dagger, granting him the power to summon and control the Dragonzord

And, as in the original series, you have to fight it. This is the only fight against the Dragonzord, because in the next chapter, you get to control it and have another zord available to fight enemies in giant form.