Imperio- One of the three "Unforgivable Curses". Places the subject in a dream-like state, in which he or she is utterly subject to the will of the caster. However, those who are strong willed may learn to resist it. The use of this curse on another human results in capital punishment or life sentence in Azkaban
Impervius (impervius charm)- This spell makes something repel (literally, become impervious to) substances and outside forces including water.
Incarcerous- Ties someone or something up with ropes.
Incendio- It was first seen in 1994 by Arthur Weasley to create a fire in the Dursleys' hearth so that he could use Floo powder there. In 1997, this spell was used several times in battle, most noticeably when Hagrid's hut was set ablaze. It was also possibly used by Hagrid in 1991 to create a fire in the hearth before bringing Harry to London.
