Next 4 dragons Crono was teaching in being a protectors, warriors and master there elements within

NightWing, Space Dragon
Element: Space+
NightWing was born in low class home but help bring it out of this style thanks to have the great power of Space by his side. He never left nor did much until his family was in a stage of get wealth. Nightwing finally goes to Crono to get his time to do something for himself.

Dustin, Dark Dragon
Element: Dark+
He is one powerful dragon who is part of the House of Dark and War as is a natural warrior by heart. He is seen as a rival to Zoey, as not only she light dragon by how both act in fights but both respect and understand the when something needs to done it becomes done reason why Crono is going to train him.

Zoey, Light Dragoness
Element: Light+
Looking like an Angel and being the House of Light and Mind she was skilled with the power of light. Respect and is a rival for Durian, Zoey wants to Train with Crono as his first Element to learn was light so learn from him would be the biggest thing to gain.

Katie, Time Dragoness
Element: Time+
Katie is the step-Sister to Rick when he was in the time of need. Katie protected and help him learn to fight for himself and much more. She soon was send with Rick to learn and understand there abilities from Crono the Elemental Dragon