I think the book you're looking for is "Shade's Children" by Garth Nix. The basic plot is that fifteen years prior to when the book is set, the "Change" happened.
"For an instant, everything stopped. Everything moving halted, every machine, every car. In that instant, every person over the age of fourteen vanished...and then the Overlords came, and herded the survivors into the Dorms. A few weeks after that, the first creatures appeared - built with teenagers' brains - and the Overlords began their ritual battles.."
Some of the children able to escape the Overlords have gained supernatural powers thanks to the Change. For example, the protagonist "Gold-Eye" (named because his eyes are gold) can see into the future (he calls this looking into the "soon-to-be-now").
With that thought Gold-Eye's Change-Vision suddenly gripped him, showing him a picture of the unpleasantly close future. The 'soon-to-be-now'.
When Gold-Eye escapes from the Overlord dormitory, he runs into a group of "Shade's Children" - other children who have supernatural powers working for Shade - a man who transferred his consciousness into a computer before the Change.
"What I am, Gold-Eye, is a human personality stored in a computer's memory. I have the memories of that real person. I think like a real person. To some degree, I still have the feelings of a real person. But no flesh, save the holographic appearance you have seen."
Shade's tell Gold-Eye that his goal is to use the children's talents to help him turn back the Change and get everything back to normal.
"I am a mature adult, complete with the sophisticated education of the pre-Change years and equipped with some of its best technology. And as the only educated adult left, perhaps in the whole world, it is my duty to fight aainst the intruders who have destroyed what we had...my duty to restore humanity...my duty to turn back the Change!"
Gold-Eye is put in a team with several other children: Drum, Ninde and Ella.
Drum escaped from where the Overlords were using steroids to enhance children's muscles for use in their monsters so he's very big and strong.
"I was taken to the Training Grounds. That's where the big strong kids go. Lots of exercise, food...and the drugs. Steroids. Shade explained those to me...what they do...what they've done to me..then when you're fourteen, they don't just take your brain, they de-string your muscles too. Muscles to put in Myrmidons."
His supernatural power is telekinesis.
"If I can see something, or I know where it is and how big, I can...think..it somewhere else."
Ninde has telepathy.
"When I reached puberty, somehow I started hearing what the creatures were thinking."
Ella has the ability to create/conjure things if she knows what they look like.
"But that blade still seems important to me. It was the first useful object I ever conjured - or created, or whatever it is I do.
It took three months of practice for me to build that picture into something real, a hard, sharp object to hold in my hand. Then one day it wasn't just a thought. It was there in my hand. Real. Sharp."
Hopefully this will help answer your question.