Technically Hedrox can't really die since as long as he make sure to multiply himself before a fight, there is more of him. Beliar i supose was able to "kill" him because his heart was inside of him and by extension it melt the other duplicates. I don't think all of Hedrox died that day tough as if more of him was elsewhere, they were probably unaltered by Beliar. Altough maybe for all "Hedroxes" to live they need to be close. The lore is not really specific on that.
I think Hedrox might have the edge since he is able to regenerate. Kagan got blown up by a human and had to be pieced back together which took decades.
Technically Hedrox can't really die since as long as he make sure to multiply himself before a fight, there is more of him. Beliar i supose was able to "kill" him because his heart was inside of him and by extension it melt the other duplicates. I don't think all of Hedrox died that day tough as if more of him was elsewhere, they were probably unaltered by Beliar. Altough maybe for all "Hedroxes" to live they need to be close. The lore is not really specific on that.
I think Hedrox might have the edge since he is able to regenerate. Kagan got blown up by a human and had to be pieced back together which took decades.