Once again a matter of preference. I'd pick Justice, but as you can tell by my signature and avatar I am biased towards her, but I'll try to make an objective breakdown.
A TJC/Toromea file's playstyle plays a lot like an advanced rush, so you'll not have a hard time adapting to playing a different concept if you decide to make a refess warriors file.
On the other hand picking Shelby can be the first step on a journey of exploring variety, i.e. Control files, which benefit greatly from the soul skill combination mentioned by Ruki. But keep in mind that going a different path is not as advised at the beginning, unless you completely dislike the current one.
Emana is a niché card, and Millia is pretty outdated, so I'd not consider those.
"Abandon all hope, ye who enter here" - Inscription above the gates of Alteil
Romdeau wrote:I don't have much else to say to you other than you live in your own world if you believe I have active enemies around Alteil besides from Demongod.