To complement the new Tortodrone helmet that is huge and therefore looks a bit odd on most armor, I suggest a special plate (like Frenzy, Thunderous and Rageous Plate) but in serene or ancient color theme. The game already has Ancient Plate, which looks different in color (much brighter), therefore Serene Plate would probably be best for the name. Important: I don't mean regular plate, but special.

// edit: added some links, because the wiki is up again (HTTP 504 earlier)