<P> Harry was frequently accused of a lack of subtlety in his magic until he began training Molly as his apprentice . Through teaching to her particular talents (especially for veiling) and weaknesses (concentration, less emphasis on violent magic), Harry gained a greater understanding and finer control over his talents and began using subtler versions of his own spells, such as tightly controlled wind gusts . </P> <P> Changes shows Harry developing the following: much better control (he starts using illusions, veils, and Luccio's cutting fire beam, raising and lowering shields with great speed; and fine uses of soulfire), huge area effect spells; pure mental summoning of extremely powerful entities without a summoning circle; and using the fire and ice exchange trick in combat multiple times . </P> <P> During the events of the novel Changes, Harry takes up the mantle of the Winter Knight . It is a position of incredible power, giving Harry access to the abilities of the Winter Sidhe, though ironically, he still complains of his aversion to cold, something the position failed to take away . This gives him substantially more stamina, speed, and strength in both the physical and magical sense, improved ability with "ice magic" which he either lacked or was reluctant to use prior to his appointment, and give him greater protection from physical attacks . It is presumed that Harry will hold the mantle of Winter Knight until he dies, as only with the death of the old knight can a new one be named (though Jim Butcher has stated that Harry is still the Winter Knight in the novel Ghost Story). </P> <P> Harry was able to employ Hellfire while possessed by the Shadow of the Denarian Lasciel, a power that especially aided destructive spells and fire effects . He first experienced this power during the events of Blood Rites, noticing that his staff had begun to generate heat and smoke when he used it, and he realized that his brief exposure to Lasciel's coin had allowed him to tap into it involuntarily . After Harry lost that power, the Archangel Uriel awarded him the Angelic power of soulfire, which is used to make a sort of magical framework for the magic being used, turning, for instance, a straight force attack into an enduring silvery construct hand able to bash and batter repeatedly . The portion of the soul used in the soulfire returns over a period of days, enabling the wielder to get back to full strength; using all of one's soul is still fatal, however . Soulfire excels when used in creation magic, a notable example of which is illusions . </P>

When does harry dresden become the winter knight