Didn't Naraku see Inu go full demon stage, when they were trying to get out of that Oni statue's stomach. This was around the time of Moruyomaru and seen at the end of the anime series. He tainted the shard Kagome had given inuyasha to put into the tetsaiga, causing Inu to go into his full demon transformation. Yet Kagome brought him back into what is called, the "purified demonic state".
I like this state. Inu has all his scruples, yet also still has the power of a full-fleged demon. Maybe this is the transformation RT is talking about. Once Inu got over Kikyo's death, and matured enough, he'd have a puberty shift and his right of passage. This may allow him to unlock Tessaiga's secret powers.
That's my speculation anyway.  Irene Sharda(Quote)

*Thinks about all times that Inuyasha has gone berserk…*

95% of Inu's transformations end with a demon being torn to shreds…

Goshinki
Gatenmaru
The Ogre

Inuyasha doesn't even need to physically touch her… If that demon gets destroyed, awful things are gonna happen to Kanna.  Starks(Quote)

But Kagome usually grabs him  and/or sits him before he actually does anything drastic.
 
I think Kanna's going to die, I just hope she turns on Naraku beforehand.
 
It would be really cool if Kanna begins to remember Kagura, and remember the abuse she and her sister took under Naraku's control. All of a sudden something broke inside of Kanna, and she goes from this emotionless little girl, to this poverful, glass, monster bent on vengence. Using up her remaining power to help Inu and gang escape.  Irene Sharda(Quote)

Irene, that's what I've been wishing for in the back of my mind as well… I'm pretty sure that she's not going to die as a martyr for Naraku.  Starks(Quote)

hm…. this chapter should be interesting.  Also, the last time inuyasha went youkai (without the help of the jewel) was when he was fighting the demon(forgot his name, but I think its something like ryu…)  that his pops sealed with his claw.  YuriYasha(Quote)

Inu last went into full youkai mode in Chapter 355, and it's high time he did it again…  Kalliope Radiata(Quote)

I think his demonic form is cool, but I like the purified version better. At least at that point he's kind of on the same playing feild as sesshoumaru. He's not crazed, but he's even stronger than his hanyou form.  Irene Sharda(Quote)

He doesn't really change that much… he gets marks on his face, and power boost. I like him better with the red eyes, he seems more cooler that way.  YuriYasha(Quote)

Yes, but he's psycotic and bloodthirsty in that state. At least his brother and father are full-blooded and keep their sanity. Inu should be able to be that powerful too, and yet not be a cold-blooded killer.
 
Oh, and by the way, I'm reading this awesome Inu fanfic called "The Temple of the Dog". Has anyone else read this? Seen the pics? It is really, really cool!   Irene Sharda(Quote)

Yeah, I saw some of the pics. They're awesome. The Egyptian themed ones, right?  Shocking Alberto(Quote)

Yes; the ones by bastblack are the best.  Kalliope Radiata(Quote)

These are my favorite pictures from the story. Still reading it, great so far.
 
http://www.deviantart.com/deviation/26148325/
http://www.deviantart.com/deviation/25287919/
http://www.deviantart.com/deviation/31084721/
http://www.deviantart.com/deviation/32551207/
http://www.deviantart.com/deviation/28271568/
http://www.deviantart.com/deviation/39389482/
http://www.deviantart.com/deviation/26446456/
http://www.deviantart.com/deviation/34087262/
http://www.deviantart.com/deviation/10861541/
   Irene Sharda(Quote)

As cliche as it is, I also love his purified form. I'm hoping he turns human at the end though, it suits him so well. =)
Is the chapter summary a little slow this week or am I just being really impatient? o.o  mintyfresh(Quote)

I doubt Inuyasha will use the Shikon Jewel to become human. That seems to selfish for me. I think/hope he will use it for a much nobler purpose.  Shocking Alberto(Quote)

Well it depends. It would've been selfish the first time (which is why I didn't think Kikyou's plan would have worked anyway), but there might be another way. I don't mind him staying as he is, but if he were to stay with Kagome it'd be sad once she got old.
Uh-oh, looks like Kanna's time is running out.  mintyfresh(Quote)

Wouldn't be sad to me. At all.  Shocking Alberto(Quote)

guys, you forget that if Naraku gets destroyed, so will the jewel(kikyo's way).  I don't think there is a way to use the jewel twice.  But then again… I wonder what Takahashi-san is gonna come up with the ending.  I hope to god it won't be like yuresei's or ranma's where the two characters run of into the sunset.  YuriYasha(Quote)

I think Inu should either stay the way he is or go into his purified demonic form, and I think the jewel can only be used once. I think he'll us it to save Kohaku.  Irene Sharda(Quote)

Indeed.  Shocking Alberto(Quote)