Izanami was important. It gave thousands Fodders one of the strongest Ocular Jutsu available.
Everything else was pretty dumb tho. Especially Obito's Ghost.
The problem with Izanami is how Kishi explained it's set up. Use a sharingan to record a series of movements (with the goal of creating a loop), casting the genjutsu that doesn't require the 5 senses being targeted, the person being trapped in the loop until they accept it. All for the purpose of punishing Uchiha who abuse Izanagi. Izanagi which permanently blinds an Uchiha in one of the sharingan they use to cast the genjutsu. Izanagi which only last a few seconds.
Obito and Danzo used Hashirama cells to amp the duration of Izanagi to 60 seconds. Not to mention Obito saying an Uchiha needs both a Sharingan and Senju chakra to make it work.
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How many Uchiha had access to Senju chakra during the Fedual period to abuse Izanagi the way Itachi describes it being abused?
Also, why would another Uchiha piss away one of their sharingan (permanently blinding themselves in one eye) to punish another Uchiha who is already half blind? Izanagi can only be safely be used once. Use it again and they'd be blind on a battle field.
Kishi should've come up with a better use/application for Izanami.
I don't consider Izanami an asspull if you know what kishi got the techniques from you would have known in was bound to happen.
Everybody knows Kishi based much of the Uchiha's MS jutsus after the Shinto Deities. Still, the mechanics of Izanami and the applications for it's inception are dumb.