Could somebody explain the Togaochi of D. Gray-man?

[WhatIsAUserName]

In D. Gray-man, a Togaochi is what is created when Innocence is used by somebody who's not supposed to be using it. They end up disintegrating in 24 hours. I've been confused after reading the manga, and seeing what happened to Suman Dark. If a person isn't supposed to be using the Innocence, why are they still able to destroy Akuma, like he did? Why did the former Exorcist turn to an enormous torso with a halo hovering above the neck? Why is the guy stuck in the somewhere in that . . . thing?

I'm sorry for asking so many questions, but it would help if somebody helped explain this to me.

[Gjallarhorn]

They problem is that they can't merge properly with the innocence, so it ends up overloading them with power. They still gain the power of the innocence, but they will be destroyed by that power.

[adl1na]

Togaochi (Fallen One) is a state of emptiness when the Accomodator (exorcist) betrayed his Innocence. Those compatible with Innocence are supposed to work for God - as a destroyer (Exorcist) of evil. Suman Dark, in the manga, pleaded evil (Tyki) to spare his life. He betrayed the location of the search group which resulted in the death of 6 exorcists and more than 100 finders. By giving away the information about the Black Order and pleaded for Tyki to spare his life, Suman betrayed his Innocence. Therefore, the Innocence punished his soul.

To cut it short, when an Exorcist betrays the light side, he will be judged and later punished by his Innocence, in which the Innocence will cause his body condition to deteriorate very fast.

For people who have been forced to be compatible with a certain Innocence, they are simply not able to withhold the power of the Innocence. Exorcists (people compatible with Innocence) are said to be chosen by God (apostles of God) - Exorcists are born to be compatible with Innocence, not made. Following this rule, the Innocence will punish the person who tried to accomodate it without its 'consent'.

:)