Crest of the Wandering Star

A skill unique to Titan Altera and the key skill in her character design.
It allows her to take on a giant form in order to destroy civilization.
This is a passive skill that allows Altera to absorb the lives, creations, and concepts she destroys as spiritron-information, making her grow even larger. It is not a skill that she can remove of her own volition.
Her HP increases by an order of magnitude2 when she absorbs the same amount of mana as her current HP.
When her body reaches a size that is twice as large as her previous proportions (at 16, 32, 64,128, 256, 512, and 1024 meters), all her parameters increase by one level as she transitions to the next part of her titan adjustment.
(For example, her Strength is A-rank, so if you think of it as 150 points, adding one level at A+ rank would double that number, putting it at 300 points.)
And if the Titan adjustment is added to that, 300 points at the first stage would become 3,000 at the second stage, 30,000 at the third stage, and so on. At the seventh stage, it would be 300,000,000.
This is an energy mass on the scale of a star, comparable to the power level of the legendary Golden White Face’s nine-tailed form (387,420,489).
This is just some extra trivia, but the “Crest of the Star” skill possessed by the Altera in Fate/Grand Order is missing one character3.

Translator’s Notes
  1. ^ Localized as Umbral Symbol, sometimes also known as Umbral Crest.
  2. ^ The Japanese says doubles, but the explanation right below it indicates otherwise.
  3. ^ In FGO the skill is called 星の紋章 (Crest of the Star), missing the character “遊” in 遊星の紋章 (Crest of the Wandering Star).
Fate/EXTELLA material: Encyclopedia of Fate EXTELLA