Solved How to make your plugin last at messing with chat?

Ok, so I've been working on a plugin, that gives players prefixes, which correlate to their ranks in-game. But simultaneously I use Factions plugin, which also changes player's name. So, how can I set my plugin, to be the last at editing the chat message? I disabled the Factions' in-chat prefix, but now the text is normal, so it apparently resets my edits.

Thanks for the help!

 

My code or the Factions' code?

 

Code:

@EventHandler
    public void apce(AsyncPlayerChatEvent e) throws Exception{
        main1 = mgbuy.getPlugin(mgbuy.class);
        String name = "";
        String divide = main1.getDivider();
        String pre_message = main1.getPreMsg();
        String msg = "";
        String full_name = "";
        String gf = e.getFormat();
        if(getRank(e.getPlayer().getDisplayName())-50 >= 0){
            name = main1.rankNames[getRank(e.getPlayer().getDisplayName())-50]+" "+e.getPlayer().getDisplayName();
        }else{
            name = e.getPlayer().getDisplayName();
        }
   
        msg = pre_message+e.getMessage();
        String name1 = ChatColor.translateAlternateColorCodes('&', name);
        String msg1 = ChatColor.translateAlternateColorCodes('&', msg);
        String divider = ChatColor.translateAlternateColorCodes('&', divide);
        //Bukkit.getPlayer("MGlolenstine").sendMessage("msg: "+msg);
        //Bukkit.getPlayer("MGlolenstine").sendMessage("msg1: "+msg1);
        if(name != null && msg1 != null && divider != null){
            //full_name = String.format("[%3$tT] %1$2s%4$2s%2$2s", name1, msg1, Calendar.getInstance(), divider);
            full_name = String.format("[%1$tT] %2$2s%3$2s%4$2s", Calendar.getInstance(), name1, divider, msg1);
        }
        e.setFormat(full_name);
    }

Here you go!
Anything wrong with the code?
It works on servers without Factions plugin.
I just realised, that there is an error on line 41:

Code:

[19:33:17 ERROR]: Could not pass event AsyncPlayerChatEvent to MGBuy v1.0
org.bukkit.event.EventException
        at com.destroystokyo.paper.event.executor.MethodHandleEventExecutor.exec
ute(MethodHandleEventExecutor.java:37) ~[spigot-1.11.2-R0.1-SNAPSHOT.jar:git-Tac
oSpigot-"2cf491a"]
        at co.aikar.timings.TimedEventExecutor.execute(TimedEventExecutor.java:7
4) ~[spigot-1.11.2-R0.1-SNAPSHOT.jar:git-TacoSpigot-"2cf491a"]
        at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.jav
a:62) ~[spigot-1.11.2-R0.1-SNAPSHOT.jar:git-TacoSpigot-"2cf491a"]
        at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.j
ava:517) [spigot-1.11.2-R0.1-SNAPSHOT.jar:git-TacoSpigot-"2cf491a"]
        at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.j
ava:499) [spigot-1.11.2-R0.1-SNAPSHOT.jar:git-TacoSpigot-"2cf491a"]
        at net.minecraft.server.v1_11_R1.PlayerConnection.chat(PlayerConnection.
java:1290) [spigot-1.11.2-R0.1-SNAPSHOT.jar:git-TacoSpigot-"2cf491a"]
        at net.minecraft.server.v1_11_R1.PlayerConnection.a(PlayerConnection.jav
a:1205) [spigot-1.11.2-R0.1-SNAPSHOT.jar:git-TacoSpigot-"2cf491a"]
        at net.minecraft.server.v1_11_R1.PacketPlayInChat$1.run(PacketPlayInChat
.java:39) [spigot-1.11.2-R0.1-SNAPSHOT.jar:git-TacoSpigot-"2cf491a"]
        at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) [
?:1.8.0_131]
        at java.util.concurrent.FutureTask.run(Unknown Source) [?:1.8.0_131]
        at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) [?:
1.8.0_131]
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) [?
:1.8.0_131]
        at java.lang.Thread.run(Unknown Source) [?:1.8.0_131]
Caused by: java.lang.NullPointerException
        at xyz.mglolenstine.mgbuy.getPreMsg(mgbuy.java:111) ~[?:?]
        at xyz.mglolenstine.MyListener.apce(MyListener.java:41) ~[?:?]
        at com.destroystokyo.paper.event.executor.MethodHandleEventExecutor.exec
ute(MethodHandleEventExecutor.java:35) ~[spigot-1.11.2-R0.1-SNAPSHOT.jar:git-Tac
oSpigot-"2cf491a"]
        ... 12 more

Fixed it... A small mistake on my part... There was no required stuff in the config.yml.