This particular helmet depicts the Sunset Queen, who is said to have died of a broken heart at the sight of sundown over the Western Sea.

Sallet decorated with a mournful visage 

Royal bodyguards are granted armor adorned with likenesses of bygone kings. It is done to symbolize ancestral protection or perhaps to remind knights of their solemn duty.

They are affected by an interdimensional infection

or something like that, yeah

thanks!