Bug: When a player has a passive or gear set that reduces the cost of ultimate abilities (such as "Power Stone" from the Daedric Summoning skill line or the Akaviri Dragonguard set), the ultimate icon will strobe/flash/blink when generating ultimate during the window of that reduction.
The strobing/flashing/blinking occurs under this condition:
The ultimate is charged for use, but has not yet reached the number of its original cost.
Example: The Summon Storm Atronach skill has an original cost of 200 ultimate to charge. With the "Power Stone" passive that cost is reduced to 170 ultimate to charge. During the time that the ultimate number is between 170 and 200, the strobing/flashing/blinking occurs.
Note: This bug also appears in the later stages (ranks, 2, 3 and 4) of the Vampire ultimate, while the player receives ultimate cost reduction, and is especially noticeable for longer periods of time when the character's vampire is in vampirism stages 2, 3, or 4.
Platform: Xbox One
Server: North America