The lore drop going on really has me on the edge of my seat. I didn't realize how much I wanted to know about how Iratu and Sakido came to be!

I like casual wear Lazuli!

So, uuhh, how exactly would the real Syndel know that caretaker angels are easy to deceive? If the whole Syndel being evil and callous thing is true, why would he care about the most insignificant (to him) of angels?

You know who WOULD know about this? An actual angel. An actual angel who somehow managed to steal immortality from Gaia (or from the real Syndel, somehow), and wanted to pose as Syndel.

I said it before and I'll say it again: Unless disproven in-universe, or directly contradicted by the-chu, I will firmly believe that angel Syndel is a fake.

You can say that again but the question is if this guy is truly an angel then was he someone important in the realm of angels

That... is a really good question, actually.
I kinda just assumed that he must've been part of the elite before, and probably at least partially responsible for the horrendous state of angelic society. But what if he was one of the downtrodden? Resentful towards other angels for the way he was treated, he tried to find a way to get revenge, and then actually found something. That is... plausible.
Wow. Yeah! Really good question! Thank you for making me consider this!

What if he's an angel who failed the Sun Emblem exam, the one thing every Angel needs? He grew without wings, and probably shunned by everyone. He wouldn't even be recognized as an adult in Heaven society. That'd explain why he showed up with no pendants, dye or tabard when he arrived in Hell. (Maybe he randomly jumped into a portal or something.)

But then whence cometh immortality?
Also where'd he find a portal? Those don't form randomly, especially after Death locked interplanar travel. And without angel-Syndel, there's also no ascension ritual.

He arrived in Hell around the same time as the last warriors to ever descend (page 946), possibly those with Darius and/or who committed the Nursery Massacre (page 967). How and why he obtained those powers seems to be the big mystery, no matter how you spin it:
-If he truly is Syndel, why is he an Angel? ("Because of Death" is the "how", but it doesn't tell us the "why".)
-If he's a random Angel, how come he's got god-like powers?

Now that I think about it, for Angels to arrive in Hell, someone must've opened those portals. It's always been Demons invading Heaven and never the inverse, only Angels using Demon-made portals. We don't know how much time passed between the arrival of the last warriors and their extermination, but if those portals are made with Father Syndel's magic, this means that he was still around when Darius entered Hell. (page 280)

Oh my God I'm starting to see a pattern here... O.O;

Syndel's plan: "I want you to become friends with them to lure them into a trap"

Little did he know, parts of his plan would get foiled by demons just stopping at the first part.

Yeah, and we can see two of them who became more than just friends with the same angel in the third panel!

Or maybe that's part of the plan. After all, what's the best way to remove an enemy?

Well that explains the St.Curtis incident

Damn, nice job bringing this full circle.
It wasn't something I ever gave much thought, but the way it's presented makes perfect sense and I could easily connect it with the St. Curtis incident.

I RECOGNIZE THOSE JERKS

Well most of them.