If not for Rudeus’ monstruous mana pool they would be all dead. He kept a water wall against three heads dragonbreathing the group.

…hard to talk about this episode without giving spoilers on what comes next. (The LN equivalent is vol12 ch9, by the way.) The fight was exciting, and it ended in such a sorrowful note (Paul is dead, Rudeus lost an arm, there’s something wrong with Zenith). A rollercoaster of emotions, really - and it shows how much Rudeus evolved, from the distance towards his Earth parents to the concern about his new ones.