In short, Sucre survives Season 4, stays fiercely loyal to Michael, suffers capture and torture, but ultimately earns his happy ending: freedom and reunion with Maricruz and their child.
Here’s a concise summary of what happens to Fernando Sucre in Prison Break Season 4:
At the start of Season 4, Sucre is in a difficult position. After being recaptured following the events of Season 3 (when he helped Michael and Lincoln escape Sona), he’s sent back to a federal prison. However, he’s soon broken out by Michael’s team because they need his help to take down “The Company” and retrieve the crucial Scylla device.