Tin Hanan/The Shadow (spoilers)

[Kein]

Alexander was the Shadow's target too, don't forget that. He not only had and extensively used an orb in the past, he also broke it. He'd been keeping the Shadow at bay for a long time already when he met Daniel. He was planning to make Daniel take the blame for both of them, it was his bad luck that in the revenge ending, it became him.

This is debatable, actually. As we know, Weyer was able to master the Orb(s) and take control not just over its powers but had no issues with the Guardians as well. Alexander as well was quite a strong person mentally (spirit and willpower), he used the orb already long before Daniel ever visited the Castle but Shadow didn't bother him before.