Judas being chosen by Christ was one of those who the Father gave to Jesus. Judas had power to cast out devils and do miracles, but Judas was lost as part of prophecy fulfillment. Jesus said that while he was with his disciples he kept them safe, but that Judas was lost. I can only gather that Judas was no longer safe at some point and if he isn't safe by Jesus he probably lost his salvation.
John 6:39
39And this is the will of him who sent me, that I shall lose none of all those he has given me, but raise them up at the last day.
John 17:12
12While I was with them, I protected them and kept them safe by that name you gave me. None has been lost except the one doomed to destruction so that Scripture would be fulfilled.
John 6:39
39And this is the will of him who sent me, that I shall lose none of all those he has given me, but raise them up at the last day.
John 17:12
12While I was with them, I protected them and kept them safe by that name you gave me. None has been lost except the one doomed to destruction so that Scripture would be fulfilled.