This power strengthens your dragon form, hardening your claws and scales, and focusing your breath weapon. This form has 30% immunity to crush damage, 20% immunity to cut damage, and 10% immunity to other types of damage. If you have one of the Dragon Descendant talents, you gain +20% immunity to the appropriate damage type, and the immunity for that damage type is no longer capped at 95%.
Each rank in this power also gives +1 auto-absorb and +1% immunity vs physical damage per rank, although the immunity bonus caps at +20% at rank 20.
Because of your sheer bulk and heavy scales, you are always classified as at least light encumbrance. However this added bulk also provides +1% health per rank, while your heavy scales give +5% armour vs crush damage, +4% vs cut, +3% vs stab and +2% vs all other damage types, per rank.
At rank 10, you gain the ability to draw spell sigils with your claws, although the actual spells are unlocked by other powers (eg Eye of the Storm rank 10+).