No One Knows

Lostrai's soul quickly merged with the new core, feeling almost no barriers or impairments. The process only took a few seconds. Following that, the puppet core activated with Lostrai inside. All the thousands of connections between the Puppet's Core and the Puppet itself lit up with life.

Finally, the Puppet opened its eyes, allowing Lostrai to see the outside world for the first time. "This... So this is how vision feels like..."

The Universe Foundation Fragment obviously didn't have eyes. Because of that, Lostrai used other types of sensorial abilities to 'see' everything around him. One could only imagine how it felt to be able to really see.