To begin with, a thousand years is the usual age for adulthood and this is only including what leads to Magna, the full tree is incredibly big and I mean nearly a thousand kind of big.
parent+parent=offspring



Dracorex+Tiamat=Malus, Jester, Lilith
Malus+Lilith=Fenix, Clich, Cherp
Fenix+Karma=Ebony
Ebony+Tiamat=Jaden, Neutrino(ever heard of black matter manipulation? This one is the first to have it. They're also the first gender fluid member.)
Neutrino+Fragilis=Crudelis
Crudelis+Jester=Calcite
Calcite+Tiamat=Magna, Opal, Wolfram(not exactly the child of Calcite and Tiamat but has been raised by them his entire life and everyone considers him an official member of the family)