Danny & Rocco
Now that they both know that Cyrus killed Sam, could one of these teenage boys go after Cyrus to try to kill him? Rocco is related to Cyrus so that puts him in an impossible situation because Cyrus is his great uncle but Sam was like a mother figure to Rocco when Lulu couldn't be. But then Rocco is the grandson of Sonny Corinthos, mob kingpin. Sonny would definitely protect Rocco and so would Jason. Plus Rocco his grandmother Laura is the mayor so she too would protect him if he were to kill Cyrus. Martin would also protect Rocco as well.
Danny wanting revenge and killing Cyrus would be similar to Michael killing Claudia especially as a teenager. Could history repeat itself with Danny and Danny ends up in Pentonville? I hope not. Same with Rocco.