no void:
package me.darkwinged.ExtraCommands.main.events;

import me.darkwinged.ExtraCommands.main.Utils.Utils;
import me.darkwinged.ExtraCommands.main.main;
import org.bukkit.Bukkit;
import org.bukkit.Location;
import org.bukkit.World;
import org.bukkit.entity.Player;
import org.bukkit.event.EventHandler;
import org.bukkit.event.player.PlayerMoveEvent;

public class NoVoid {

    private main plugin;

    public NoVoid(main plugin) {
        this.plugin = plugin;
    }

    @EventHandler
    public void onPlayerMove(PlayerMoveEvent event) {
        Player p = event.getPlayer();
        Location loc = p.getLocation();
        World world = Bukkit.getServer().getWorld("world");

        if (loc.getBlockY() <= 0) {
            p.teleport(p.getWorld().getSpawnLocation());
            p.sendMessage(Utils.chat(this.plugin.getConfig().getString("spawn")));
        }
    }

}

chat format:
package me.darkwinged.ExtraCommands.main.events;

import me.darkwinged.ExtraCommands.main.Utils.Utils;
import me.darkwinged.ExtraCommands.main.main;
import org.bukkit.entity.Player;
import org.bukkit.event.EventHandler;
import org.bukkit.event.player.AsyncPlayerChatEvent;

public class ChatFormat {

    private main plugin;

    public ChatFormat(main plugin) {
        this.plugin = plugin;
    }


    @EventHandler
    public void chatFormat(AsyncPlayerChatEvent event) {
        event.getFormat();
        Player p = event.getPlayer();

        event.setFormat(Utils.chat(this.plugin.getConfig().getString("format")));

    }

}