In a Ba'al fanfic with 'all the time in the world', the possibilities are quite vast. Firstly, Ba'al might use this time to study ancient and lost knowledge. He could search for secrets that were previously inaccessible due to time constraints. Secondly, he might use the time to observe the evolution of civilizations. He could manipulate their growth from behind the scenes, subtly influencing their cultures and technologies. And finally, he could use this time to confront his own past and make amends or double down on his previous actions, depending on his nature as portrayed in the fanfic.
Well, if we consider 'all the time in the world' in a Ba'al fanfic, it could be a very interesting exploration of his character. Ba'al is often portrayed as a powerful and somewhat devious character. Given infinite time, he might start to reshape the world according to his own desires. He could start to create new alliances or break old ones. The fanfic could show his journey through this endless time, facing new challenges and opportunities that come his way.