Adonis from The Kingdoms of Ruin (Hametsu no Ōkoku) has a very powerful plot armor.
The Kingdoms of Ruin episode 3 spoilers ahead!
The third episode of The Kingdoms of Ruin consists mostly of the main character, Adonis, successfully destroying everyone who tries to stop him. The girl who promised him to revive Chloe is dead, so he simply goes around killing people.
As Adonis weaves his spell, nobody seems to be able to penetrate his magical shield. Firing at him is worse than useless; he sends the bullets back at the attackers. And still, the people sent to deal with Adonis just keep firing bullets they know will turn back to kill them. That is the first instance of plot armor, and rather than affect Adonis, it affects the people around him, who are just too silly to get the message of what Adonis can do.
The mindless slaughter of anyone who fires a bullet at Adonis continues until the machine that is meant to stop magic is powered. It breaks all the spells Adonis had been weaving, leaving him defenseless. However, the plot armor is at work, and nobody gets the idea to shoot him while he is powerless. As a part of a building falls to cover Adonis from the view of the people who are still not shooting him, one of the soldiers starts running at Adonis.
Adonis, as he figures out his surroundings, realizes that his quill is on the ground, and he starts reaching toward it. At the same time, the soldier reaches him and rather than escape in one way or another, Adonis just lies there, ready for the soldier to execute him. Just minutes ago we saw Adonis dodge bullets; now, he cannot dodge a blade.
For a short while they get you fooled that Adonis is actually dead. There is a body, after all. However, at the very end of the episode, it is revealed that the body is not real, and Adonis is still alive.
Plot armor does not have to be a bad thing. Essentially, every main character has it. However, in this episode, the characters are deliberately acting strange, even silly, which does not look very good. Let’s hope that in the future, The Kingdoms of Ruin will avoid this sort of plot armor.