Call of the ancestors is a spell that only Fire Gnassies can do. It changes the wielder of the spell either into a dragon or a phoenix. Wich one will be determend when the spell character answers these questions before the first time of casting it:
Power to avenge or to heal? Get more powefull or get smarter? Do you want to help people in danger or do you only watch out for yourself?
If the majoridy of the answers is selfish the player can then turn into a dragon and if selfless they will turn into a phoenix. The DM decides wich is answer is selfish or not is up to the DM.
At first the character will be a hydrid form between race and beast. Every 4 levels the spell will be more powerfull and the best will be more whole. The dragon will boost strength, dexterity and constitution. The Phoenix will boost intelligence, widom and charisma. At level 16 the beast is whole and the bufs wont go higher.
Wheter what stat is the highest of the player's character-sheed determence the look of the beast (like if strength is the highest the dragon/phoenix will be more beafy), how it looks in total is up to the DM.