I was thinking about this after watching a Playthrough of KQ6....
Shamir's mission, if you will, is to kill Alexander, is it not? In any event, Alhazred views Alexander as a threat pretty much as soon as they meet--Probably due to Graham foiling Mordack*, as well as Alhazred's desire to keep Cassima under lock and key.
Not only is Shamir sent out to the other Isles to tell their leaders that Alexander is a dangerous foreign saboteur (which leads all of the leaders to either try to kill him or distrust him), but we also see Shamir attempts to lure Alexander to his death multiple times:
-Tries to get him to jump into the ocean, which would cause him to drown.
-Tries to get him to eat the nightshade berries, which would poison him
-Tries to get him to go into one of the trap rooms in the Minotaur's lair, which would lead to him falling to his doom
-Tries to get Alexander to come into the Isle of the Beast's garden, which is booby trapped with those stone archers--If Alex/the player falls for it, Alex would be shot and killed by the archer.
-Is about to zap Alexander out of existence but is stopped by Alex either taking command of the Genie with his lamp, or, alternatively, killing him by intoxicating him with the Mint, thus causing his spell to backfire on him and kill Shamir himself.
My question is, if part of Shamir's mission is to ensure Alexander gets killed, why doesn't he just zap Alexander out of the living world with one of his spells in one of their many encounters? Seems a much easier and foolproof way of taking care of Alexander than trying to trick him to his death.
*= I think there are three motives in wanting Alexander dead on Alhazred's part. One, revenge for Mordack (even if it was Graham's doing). Mordack getting killed very likely set Alhazred's plans back--He was counting on Cassima never returning, thus removing any barrier to his claim to the throne with the King and Queen dead. When she unexpectedly returned, that set him back and he had to cobble together the Marriage plot in order to make himself the legitimate King of the Green Isles.*
Two, letting Alexander live given his desire to meet Cassima and their past friendship is a possible danger to his plans, since a big part of his plan is keeping Cassima in seclusion.
Third, if the first guy who was supposed to keep Cassima away was desposed of by a member of this family, who's to say this young Prince couldn't somehow muck up Alhazred's plans as well? (which is what Alex ends up doing). How was Alhazred to know what Cassima told him in Mordack's Castle? Perhaps she told him something damaging about the Vizier. In Alhazred's mind, perhaps Alexander came there with the express intention of saving Cassima rather than simply visiting her.