the Undying
In chat YourName the Undying
The suffix “the Undying” after your name, in chat and on the tab list.
A cosmetic suffix. It changes how your name reads and nothing else — no stats, no drops, no head start on the ladder.
Applied to the Minecraft account you linked, and it stays with you through every rank-up.
The same titles are also available in-game for Credits. Buying one here is a convenience, never a shortcut.