How hard is the icon of sin on doom eternal?

[Dr.Ferret]

I can tell he’s pretty hard but how hard exactly?

[Frag Maniac]

As always depends on skill level, what difficulty mode you're on, and how much you know about the game. For me it varied from a battle that lasted well over a half hour on my first play through on Hurt Me Plenty, to about 7 minutes on my last play through on Nightmare. It certainly helps to bring a fully loaded BFG into the battle, and shoot it at him from up high and close, then move immediately. A lot of heavies spawn, but the BFG, staying on the move, and the now and then Crucible swings keep them under control. The main attacks you need to watch out for are his punches in the first phase, and mortars in the second. Of course he can also fire a mean ballistic attack from his head, but it's just a matter of being aware of when he's doing it and not directly exposing yourself to it.

[igg]

I think the final battle is pretty easy. I just run from Crucible ammo to Crucible ammo and in between I fire a few shots at the IoS.

[Kristian Nebula]

I noticed it is sometimes much easier and sometimes much harder. I've played it all but once (the first playthrough, UV) on nightmare or ultra-nightmare and it seems to rely on some kind of RNG on what monsters it will spawn. Sometimes it's only Zombies and Cacodemons. Sometimes only Barons and Cyber-Mancubi + Carcasses, lol. And everything in between.

[Martin-CAI]

Compared to what?

[Robo_Cola]

If you have a solid strategy he's much more bearable regardless of difficulty level.  Use the chaingun shield when you are shooting the icon of sin so you mitigate any damage he inflicts, blood punches and the crucible should be the only thing you use for the ground fodder since you have unlimited spawn-in charges.

 

You wanna be patient when you decide to attack the icon.  The biggest threat in this battle are the enemies that attack you while you are vulnerable attacking the icon.  So make sure you take them out first then ready your chaingun and shield, standing near the corner of the map when you can also helps so enemies don't sneak attack you from behind.  That's how I do it anyway and it seems to work quite well, occasionally I'll use the BFG on him if I'm extremely close in proximity to him.

[Frag Maniac]

Get to know the battle areas too. There's places that are advantageous to get to, like the spot in the corner high up and to the right in the first phase. It has to be dropped down to slightly from the highest level, but it has a health cache and a wall that protects you from ground enemies. ANY spot in this battle is not safe for long though. The best strategy is staying on the move so you can spend more time attacking IoS, rather than surviving the ground attack via the Crucible. Use the jump pads in the corners to get to the top level quickly. This battle needs to be balanced well. If you lean too much toward taking out heavies with the Crucible, it will only drag the fight out much longer.