Thanks! This is what I want to re-confirm.Im pretty sure the your can bring a weak member for your ally seraphine to replace, it doesnt count as dead as long as the number of units you start the stage equal the number of units you finish with (e.g start with 2 units, finish with 2 units)The trick for no units dying trial if you have a Seraphina is:
Use 1 Seraphina(4*+2 of course) ONLY, empty the rest of the team. Choose another Ally Seraphina.
Gonna try it tonight!