I'm playing Wrath of the Righteous, and it seems a Sage Sorcerer can still enter Dragon Disciple and gain all the benefits of being a sorcerer of the combined level, bonus spells, Arcane bloodline ability, grow claws and so on. Is this correct?
Nope
Requirements
To qualify to become a dragon disciple, a character must fulfill all the following criteria.
Race: Any nondragon.
Skills: Knowledge (arcana) 5 ranks.
Languages: Draconic.
Spellcasting: Ability to cast 1st-level arcane spells without preparation. If the character has sorcerer levels, he must have the draconic bloodline. If the character gains levels of sorcerer after taking this class, he must take the draconic bloodline.
For the most part Chell is right. The only exception would be if you had two bloodlines. The only way I know to do that would be a crossblooded sorcerer. Even then the sage bloodline may not be an option. Technically both the crossblooded and wildblooded archetypes modify the bloodline. Many GM’s might let that slide.
I knew something was wrong with this.
Yeah, even if you add a level of bard and use it as base for the prestige class, Dragon Disciple's requirements want you to pick draconic bloodline for your sorcerer.