Only visible when actively showing content (e.g., ShowSubtitle).
Hidden when done (e.g., HideSubtitle).
Appears when showing content (e.g., NPC.ShowSubtitle).
Hidden only when content is shown in a different UI section (e.g., PC.ShowSubtitle).
Appears when showing first content.
Never hidden after that.
Appears when dialogue UI opens.
Also sets portrait names and images.