Some said death is the end; some said during your last moment, you will see your life flash before your eyes; however, Alex experienced none of these things. It was questionable whether or not he was genuinely dead after receiving that unexpected attack from Priscilla, which crushed his heart.
At the moment, Alex was inside a void, only darkness; he couldn't see his body. He tried to call Silveria many times but failed; naturally he was also unable to communicate with Nyx.
Alex doesn't know what state he was currently in, sighted before reflecting upon everything that happened to him recently. At least by doing this, he could kill some of the boredom he felt.