"deadly storm has a passive that says every time they are hit they gain a stack of Born for Combat. At ten stacks, they gain an Area Effect skill that deals heavy damage to all enemies around them. This means the more people that are hitting the champion, the more damage they output through this passive."
The champ should gain the passive for how many targets he hits, not how many targets hit him. The most typical case is the tank is holding agro while champ is going aoe crazy, but in that case the champ is not receiving the hits.
[I][COLOR=green]'I have come,' he said. 'But I do not choose now to do what I came to do. I will not do this deed. The Ring is mine!'[/COLOR][/I] Frodo, turning to the dark side