Relationship between Izanagi & Izanami
I´ve seen some posts and i´ve noticed not everyone understood Izanami and it´s connection with Izanagi and the users of the technique.
I´ll try to explain it here, from what I understood from Itachi´s words:
1- What happens to the user of Izanagi if Izanami is used?
Izanami nullifies Izanagi, and makes the user of Izanagi accept what´s he´s trying to avoid with Izanagi, in other words, his destiny. Makes the user accept the unfavorable conditions that he avoids with Izanagi.
2-Why does using Izanagi need to be punished?
Because overusing Izanagi makes the user of the technique arrogant, and the user starts to think he can deny his destiny, the bad things, and only thinks good things will happen to him, which is a bad thing because without mistakes, a person can´t grow and learn, we could say the user enters in his own personal "loop".
3-Lost of eye sight isn't worst?
There are most important things than power, for example, acknowledging yourself and know your limits, something Izanagi doesn´t let you see. It turns you blind in more than one way.
4-If person didn't use Izanagi wouldn't they be dead or maimed?
We´ve seen Izanagi been used for defensive purposes only, it doesn´t means it doesn´t have other applications, considering it is a technique derivated from the RS´s Creation Of All Things, it is plausible that it has a more varied use than just avoiding death.
5-How does that help the clan?
Izanami helps the clan in the way that his members know their limits and don´t do everything for themselves, it helps the clan members to not deceive themselves and understand the differences between their reality which is an illusion made by Izanagi, and the "true" realitywhich they´re trying to avoid.
It´s better to die than to live in an illusion, that´s not living in any way.
6-How can you repeatedly use a technique that you can only use twice at great cost?
The only logical explanation would be that the users of Izanagi would take Sharingan eyes from his comrades, so their power and the power of Izanagi doesn´t disappear.
Which actually makes sense, they would be taking other people´s power (Sharingan) and add to their own, much like Kabuto did. Itachi has probably seen that the situations were much the same, and performed Izanami because the actual scenario fits in the reasons as to why the technique was created.
I hope this helps you all.