Women (Karen in particular), fine wine, down time, surprise attacks (his, not his enemy's)
Men (Ranma in particular), beer, being busy, people who can see through his shape-shifting (again, Ranma seems to catch more ire than normal)
Pistol, Blackjack (magically envenomed knife), wrist shields with energy blades
Shaolin Kung Fu, some Ninjitsu
High, with a suprise attack. Like all assassins, Emrey suffers substantially when he has to fight a battle on equal ground. That this doesn't bother Ranma's assassin-esque fighting style is just one more thing he holds against him.
Psychic powers: Telepathy, including full-blown mind reading. Emrey picks up surface emotions and some visual imagery of thought without substantial effort. Actually reading thoughts requires substantial effort. More advanced and dangerous techniques allow the rakshasa to probe minds and even take them over to some extent.
Shape-shifting: As a rakshasa, Emrey can morph at will into any man-sized creature he can imagine, although he does not necessarily gain any abilities or strengths of that creature/individual.
Having joined Karen early on as a contract assassin for the IEF, the rakshasa's early career was quite successful... until someone figured out he wasn't a human master of disguise, but actually a non-human shapeshifter. Despite the fact that as a mercenary, he was under no obligation to disclose this information, he was accused of trying to infiltrate the IEF and would have been killed if Karen hadn't come to his defense, pointing out that Emrey had performed his services perfectly and had been given no secrets to betray to the enemy. Ever since then, the demon has been hopelessly infatuated with the gorgeous sorceress, despite the fact that he regularly seduces other women when he can (usually tricking them with his shape-shifting skills). Ranma is a constant thorn in his side, despite the fact that he hardly knows the man and vice versa; Ranma's impressive record of service, flawless field assassinations, ability in basic combat, and extremely enviable sexual relationship with Karen Molsk all grate at him constantly.