One striking aspect of the villain Loki in the early Marvel comics, was that Loki was Thor's half brother and also a god. So Loki was 'family' and also could not be killed (at least, not until the end of all things).
So when Loki became a rebel against the authority of God (Odin), became consumed by pride, and overwhelmed by resentment and jealousy against Thor; and when he began to derive his main satisfactions form 'mischief' - tormenting people destruction, disorder...
Well, there was no way of solving this problem once for all. Loki could be 'contained' but never stopped.
All that Thor, and the other gods, could do was serially to defeat Loki's plans one by one, heal his destructions one by one - and try and try again to persuade Loki of the error of his ways by logical demonstration, periods of punishment, exile, explanations, and even by showing him Love... pretty much everything gets tried at one time or another.
As a child I found this very frustrating. I wanted Loki to be sorted-out. Now I appreciate the deep realism of Loki's indestructible malice.
In the end it is up to Loki. Nothing can force him to change, nothing can force him to abandon resentment and hatred as his core satisfactions, nothing can force him to recognize that he is his own worst enemy (as well as everybody else's worst enemy).
Indeed Loki is Loki's only real enemy.