From Figure Ou 155

Birth's main purpose is to gather medals.
It's able to draw out the hidden powers of Cell Medals.
Only Cell Medals are needed to transform, use the weapons and to activate the special attack. That's because Kogami said "Core Medals are for OOO, Cell Medals are for Birth."
The candidates for Birth are Ankh, Eiji, Kogami, Maki and Goto. (Not in a specific order).

The Drill Arm has magnetic features that pulls Cell Medals towards it.

Shovel Arm is used for when a Yummy is defeated and all the Cell Medals are scattered.

Nobunaga, the user of Birth in the movie.

The victims of medals.
A struggle revolving medals has caused many victims. Humans are the only ones, Greeeds are no exception.
Kazari took many of Mezool's Core Medals for his plan.
She's only left with 1 Medal, however unlike Ankh, she didn't turn into an arm. She starts to think there's something more to Ankh.

Goto believes that Maki is the ringleader of Hina's abduction.
When Goto arrives in front of Maki, he's told that the Birth Driver is complete and Maki tells Goto "I could give this to you, I believe we could make good friends."
What will Goto do!?

If you are wondering about the Japanese text on the picture, it says "Do not reupload on Ameblo." Doesn't say anything about other sites, so I assume it's alright if it's on HJU.