Oh, sorry, Azerty, I didn't check the thread recently, thought that with the walkthrough players won't have any more problems.
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1) Well, you can just try some options and see what happens, most of them end with death, however...
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2) The eye. You can "look" at skills to get their description, much like with regular inventory items.
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3) When you charm him, you'll know it.
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I'm a bit perplexed with you having this problem, to be honest. You should just use the Eye on him and voila. Maybe you don't have enough blood to use the skill?
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