Sigurd hands down.
He fights a war for a kingdom that turns on him for bieng an honest good guy and can't do shit about it,
He's forced to fight his brother in arms Elto and has to deal with him bieng murdered by his own king and can't do shit about it.
He fights knowing his wife is lost and had to deal his best friend and sister get cowardly murdered and can't to shit about it.
He fights knowing cowards murdered his king and placed the blame on his father who also dies in front of him.
He fights knowing he will never see his son again becuase fighting the entire country surely means death sooner or later.
To top it all off before he dies Alvis brings his wife to his face and says haha i stole your wife. Then cowardly kills sidgurd and most of his army.
Sidgurd has his friends and family taken away from him, his homeland robbed of him, his good name ruined, and his life stolen.
Sidgurd truly has the saddest of tales. He was stripped of everything that made him the Holy Knight he fought to be and died with almost nothing.
...you best your arse I killed Alvis over and over again with celice.