Blood of the Jinn

The Blood of the Jinn was a phenomenon unique to members of the Iuchi family. Despite its name, it had not been said whether Iuchi with this blood were descendants of jinn or if that was simply a nickname. Whatever the exact nature of this condition, its bearer was born with a great connection to meishodo, magic from the Burning Sands. Secrets of the Unicorn Clan, p. 49
Normally, meishodo abilities could not be memorized. Rather, one must be holding the meishodo trinket and briefly meditate on it to create its effect. Also, unlike calling upon the kami, meishodo effects could not be altered and were cast at their most basic level. 
Those with the Blood of the Jinn, however, were able to actually cast any meishodo spell without holding its associated trinket. When these shugenja did cast the spell while holding its trinket they were actually able to manipulate the spell as a normal shugenja could. 
This blood was abominable to the rest of Rokugan. Its users did not follow the way of the Kami at all, and were thus considered wizards to the rest of their countrymen. Any such users of meishodo must take care to conceal their abilities and make it seem as if they were calling upon the kami when using their arts in front of non-Unicorn, lest they be executed.