Heidern has always been there pushing the story alonglol he was relevant with Clone Zero in '00 and that's it. His role with Rugal was "you took my eye and killed my family", what has he actually done in the story ?
If I struggled to the end of my determination, to the end of my way of life with my followers, if the result is ruin, then this ruin is inevitable. Grieve. Shed tears. But you cannot regret.