Some gameplay videos of Tales of Berseria have been put up by IGN and Polygon featuring English text and voices. It's not easy to hear all the characters clearly, but it gives an idea what they sound like until an English trailer is released (the one uploaded by Bandai Namco today is a subtitled version of the fifth trailer).
A new magazine scan reveals some new DLC costumes to be released on September 1:
The usual set of costumes of previous Tales characters has been announced to be 300 yen each. The list is--
Velvet: Rutee (Tales of Destiny)
Laphicet: Richard (Tales of Graces)
Rokurou: Ludger (Tales of Xillia 2)
Eleanor: Natalia (Tales of the Abyss)
Magilou: Arche (Tales of Phantasia)
Eizen: Hubert (Tales of Graces)
There is also a Mieu costume/head. The head and Sorcerer's Ring seem to be attachments separate from the costume itself. The body suit is for Laphicet only.
(The Normin costume pictured above that is obtained ingame.)
Lastly there's a set of magicians' costumes for the girls in the party. These will also be 300 yen each.