Question Getting Killers to display in a list?

Hello to who ever is reading this
I have been trying to use an event "PlayerDeathEvent"
to get the "Player Only" name that killed the player
then using the .getKiller().getName()
To put them on a command that when a player types the command
it displays a list with the killer / killers if multiple names on
but i have not even got it to display there name in chat
I Mean I'm just asking for some examples ? pointers of where to look how to do this anything that can help me please ?

 

.getKiller().getName(%player%)
try this XD
if not try this
.getKiller(%player%).getName(%player%)
and try also use display after it

If you need more help send me the file ill fix it for ya

EDIT by Moderator: merged posts, please use the edit button instead of double posting.

 

Code:

        PlayerStorage storage = getPlayer(e.getEntity());
        if (storage != null) {
            if (e.getEntity().getKiller() != null) {
                PlayerStorage killer = getPlayer(e.getEntity().getKiller());

Took this from a kitpvp code but you can just remove storage and playerStorage and replace them, like String killer = e.getEntitity.getkiller adding the () ofcourse. Then if u want a list you can do a List<String> players and add them to it first checking if they arent already on the list.