The final being is not as hard as you might think. Be sure to watch out for the squirmy blue things that shoot out red things; they can take 100-300 HP off. You can easily dodge them by running around them. After the UB has taken in a certain amount of damage, a movie will play. Daniel will throw down the Mitochondria bullets that Aya will need to finish the U.B. off. Shoot the being eight times with the MitoBullets until he falls.
DONT CELEBRATE JUST YET.