Manga Watch

Ryan sees the mysterious watch device through the smoke and dust. He picks it up.
"Aahh!!" Blood is drawn out from his wrist as the device is worn on it, causing blood to spill.
Ryan notices a flashdrive on the watch.
"Carsonn. That's my family's name."
He turns around and sees three dead bodies on the floor.
"No!!!!!" Ryan feels tears bubbling up in his eyes and lets them out.
[Do you wish to save their lives? The Cost: ???]
[Yes] [No]
Ryan reads the strange watch and instantly accepts.
[Power transfer commenced]
Bright light leaves the watch and enters their body.
"Cough cough." The bodies get up.
"You guys. You're alive again. This is all my fault."
Ryan smiled.

How does Ryan use the Manga Watch to help himself?
Does it connect to his late biological parents?
What was the cost of bringing his friends back?
And who created this device?