Help building from a base of Teal Quetzalcoatl and Alilat

So I've had my Quetzalcoatl for a while now, and still seems common in high rank teams. I did notice in these teams, almost all also carry Alilat, and I can understand reasons as to why.

There seems to be some different directions with the other two though. Some I noticed fill it with their heavy magic and phys attacker, but also noticed some with full magic strength or other types of support involved.

What are some tips and ideas as to choices on the two other members? Dx2?