How should one feel about Iran in this conflict?

Assalamualaikum warahmatullahi wabarakatuh.

I'm not well educated on Iran's history. I've only heard snippets from comments here, but it seems like many would rather support Iran instead of Israel and the US.

So far what I know is:
Iran is Shia, this is well known to most.
Iran is the last line of defense against Israel and the US in the Gulf.
But, from what I've heard, Iran has done atrocities to Syrians and Sunni Muslims?

Do let me know more about the third point, and tell me if there's nothing wrong about the 2nd one. Jazakallah Khair.