Cloudrest Illusionist, like Calm, is most useful for killing other creatures without having your own take as much damage, if any is taken at all. This card is especially useful for getting around creatures with lethal or an exceptionally high damage. Do not make the mistake of thinking the damage reduction will carry over to the opponents turn, the targeted creatures damage will only be reduced during your turn. The fact that Cloudrest Illusionist has a decently high damage also makes it a very good card for the amount of magicka it costs. When a players rune is destroyed, and this card is drawn, it may be played immediately, or may be put in the players hand.