Naruto V: Eye See Your Sharingan and Raise You a Rinnegan

[Traab]

I'm pretty sure the pills could kill someone as skinny as Shikamaru

They would kill someone as fat as an akamichi. However, its an 8 gates kind of effect, your entire body gets converted to chakra pretty much, so for that brief period of time, you can do just about anything. Like say, fillet the juubi with shadows. If anyone could make incredible use of 5 seconds of supreme power before dying, it would be shika.