ABANDONED. (YA Sci Fi) Future where protagonist has near death experience and starts seeing creatures

[Andrew]

Far in the future. Protagonist nearly dies and starts seeing creatures. has a companion who is an old man in a toddlers body (medical treatment stopped aging and made super smart) There is a massive satellite for information. SPOILER at one point in the book the protagonist throws a grenade into the barrel of a tank and the antagonist says this is near impossible. Protagonists man goal is to save the creatures from a corporation who wants to use the creatures for energy
Read this book around 2006-2011 I believe. Any help would be great!

[Cupcakedoll]

[Kris]

No response, moving to Abandoned folder.

Andrew (OP) was last active on the site in January 2021.