Catholics are obliged to believe in the guilt of Judas, as he betrayed the King of Kings. Jesus says "woe to that man by whom the Son of Man shall be betrayed: it was better for him, if that man had not been born." Although the Gospel records Judas as repentant, he is often seen as the "son of perdition" whom Jesus says he lost.
This, to me, gives the impression that everything we do is already planned and that free will does not exist. That lets Saddam Hussein, Hitler, every other despot and murderer and all others who commit crimes large and small, off the hook.
In God's eyes, the major sin of Judas will have been that of despair - he was repentant, but felt himself unworthy of God's forgiveness and hanged himself from a tree. Suicide is a terrible sin which denies any possibility of reconciliation.
Jesus said, “Forgive them; they know not what they do." Seems to cover everyone, including Judas Iscariot - and me.
If it was truly invested that the Son of God would be crucified, then surely Judas Iscariot was the ordained instrument.
Jesus asked God to forgive him, "because he (Judas) didn't know what he was doing."
Judas tried to force Christ's hand, (to take over the kingdom of earth,) but he didn't know, that wasn't God's plan for the moment. He fell into the predestined role, unlucky for him.
He will have to pay something for what he did. Forgiveness doesn't mean that you don't get back what you give. "What goes around comes around" is one of the greatest law there is. Now someone else (highly evolved) can take the effect of that "sin" (cause) upon himself, so that the "sinner" can ascend to a greater level without a very great strain upon his body, however much it was deserved. Judas probably needed to ask. If Judas would've known Christ well enough, he would've known and believed that Christ would've surely forgiven him, therefore he could've been able to forgive himself instead of hanging himself.
Asking for forgiveness from God, is a sign of belief that it can be done. Believing in it, is same as having it done.
Now the main point should they be forgiven?
I think yes, because God is fair.
The Bible says: "If we confess our sins, He is faithful and just to forgive us [our] sins and to cleanse us from all unrighteousness. (1 John 1:9). Remember that Peter also denied Christ three times (which is also betrayal), but he repented, was forgiven and became a leader of the disciples.
This is important to understand because we sometimes think that we can do something that God cannot forgive. God will forgive us unless we blaspheme the Holy Spirit. But it is not certain what blaspheming the Holy Spirit entails. Those who have participated in the Blasphemy Challenge and have denied the Holy Spirit and Jesus Christ online can be forgiven if they are did not understand what they were doing. Most of those people have had a painful experience in life and have blamed God for it without ever really knowing God. I believe blaspheming the Holy Spirit is more of an on-going rebellion against Jesus once a person understands who Jesus is.
The only way a person cannot be forgiven is if God hardens their heart, like He did Pharaoh in the book of Exodus. It is possible that God had hardened Judas’ heart, but that is not for us to know. Our only fear is that we continually sin in rebellion against God, because one day God may take away the ability for us to even ask Him for forgiveness, or the ability for us to even believe in Him by hardening our hearts.
God is very patient, like a lamb; but He is also terrible, like a lion. He is real, and He is not mocked, so we must all beware.