The perceptions of Lord Alars among the family of Amber tend to vary. To Jacqueline, he was the man who imprisoned her and her great-grandmother, stole her father's Patternblade, and pulled the Jewel of Judgement out of her eyesocket. To Hiko, he was the captor of her child, whom she was able only to succeed in rescuing by setting off a spell that destroyed much of the castle and took many lives. To some others, he might seem a good man driven past the breaking point by events no one could endure.
Whatever the reasoning behind it, Hiko's act, which killed six of his children, appears to have been the turning point for Lord Alars. He became obsessed with vengeance against the Royal House of Amber, attacking by trump both those connected with the deaths of his children (Jacqueline), and those who played no role (Beowulf).
Later, after his daughter Suu befriended Motoko, and Beowulf returned some heirlooms to House Alars that had been stolen by the Master, Lord Alars appeared to reach some kind of new resolution: at the memorial service for those killed in the Second Battle of Demogorgon, he accepted Motoko's blessing as Bride of the Serpent, and asked that they apologize to Beowulf for the attack upon him.
Two days later, he attacked Morgan by trump after Morgan had gone astray in Shadow due to the Blood Curse of the Serpent who had guarded the Air Patternblade. In the process, House Alars gained a second Patternblade to go with Justice, and Lord Alars was killed. His widow, Lady Kodachi, is now in control of the House until his heir, Lady Talia, reaches the age of majority. Talia's hand in marriage (and, thus, control of the House) has been offered to anyone who can deliver the head of Morgan.
In final estimation, Lord Alars appears to have been a man driven to obsession, vengeance and madness by the loss of so many of his loved ones. He was clearly beloved by his wife and daughters, and acted, from his point of view (and that of many others, undoubtedly), to avenge the mass murder that Hiko did in rescuing Morgan. His death was tragic (though perhaps also inevitable), and will undoubtedly worsen the ever-precarious relations between Amber and the Courts.