Rewrite

[Techcable]

Combat Tag's current codebase is a mess.
The CombatTag class manages the entire plugin violating the single responsibility principle.
Getters and Setters are missing, the packages don't follow convention, and the code isn't extensible.
I suggest moving to something like CombatTagReloaded, where CombatTagging has an event, that other plugins can hook into.
Compare the combat-tagging code in CombatTag, which handles plugin compatibility, settings, and permissions.

        if (plugin.npcm.isNPC(damaged)) {
            return;
        } //If the damaged player is an npc do nothing

        if (plugin.ctIncompatible.WarArenaHook(damager) && plugin.ctIncompatible.WarArenaHook(damaged)) {
            if (!damager.hasPermission("combattag.ignore")) {
                if (plugin.settings.blockCreativeTagging() && damager.getGameMode() == GameMode.CREATIVE) {
                    damager.sendMessage(ChatColor.RED + "[CombatTag] You can't tag players while in creative mode!");
                    return;
                }

                if (plugin.settings.isSendMessageWhenTagged() && !plugin.isInCombat(damager.getUniqueId())) {
                    String tagMessage = plugin.settings.getTagMessageDamager();
                    tagMessage = tagMessage.replace("[player]", "" + damaged.getName());
                    damager.sendMessage(ChatColor.RED + "[CombatTag] " + tagMessage);
                }
                plugin.addTagged(damager);

                if (plugin.settings.blockFly() && damager.isFlying()) {
                    damager.sendMessage(ChatColor.RED + "[CombatTag] You can't fly in combat!");
                    damager.setFlying(false);
                }
            }
            if (!damaged.hasPermission("combattag.ignore") && !plugin.settings.onlyDamagerTagged()) {
                if (!plugin.isInCombat(damaged.getUniqueId())) {
                    if (plugin.settings.isSendMessageWhenTagged()) {
                        String tagMessage = plugin.settings.getTagMessageDamaged();
                        tagMessage = tagMessage.replace("[player]", damager.getName());
                        damaged.sendMessage(ChatColor.RED + "[CombatTag] " + tagMessage);
                    }
                }
                plugin.addTagged(damaged);

                if (plugin.settings.blockFly() && damaged.isFlying()) {
                    damaged.sendMessage(ChatColor.RED + "[CombatTag] Disabling fly!");
                    damaged.setFlying(false);
                }
            }
        }
}

To the code in combat tag reloaded, which fires an event that other classes and plugins can handle and modify easily:

    public void onDamage(EntityDamageByEntityEvent event) {
        LivingEntity attacker = Utils.getRootDamager(event.getDamager());
        LivingEntity defender = (LivingEntity) event.getEntity();
        if (CombatTagAPI.isNPC(defender) || CombatTagAPI.isNPC(attacker)) return;
        if (attacker instanceof Player) onAttack(CombatPlayer.getPlayer((Player)attacker), defender);
        if (defender instanceof Player) onDefend(CombatPlayer.getPlayer((Player)defender), attacker);
    }

    public void onAttack(CombatPlayer attacker, LivingEntity defender) {
        if (!(defender instanceof Player) && !Utils.getPlugin().getSettings().isTagMobs()) return;
        if (attacker.isTagged()) return;
        CombatTagEvent event = new CombatTagEvent(attacker, defender, TagCause.ATTACK);
        Utils.fire(event);
        if (event.isCancelled()) return;
        attacker.tag();
    }

    public void onDefend(CombatPlayer defender, LivingEntity attacker) {
        if (!(attacker instanceof Player) && !Utils.getPlugin().getSettings().isTagMobs()) return;
        if (defender.isTagged()) return;
        CombatTagEvent event = new CombatTagEvent(defender, attacker, TagCause.DEFEND);
        Utils.fire(event);
        if (event.isCancelled()) return;
        defender.tag();
    }

Of course, I would like @Outfenneced 's opinion on this, as i am proposing a complete rewrite.

[Techcable]

@Outfenneced
#8 #5 and #7 are on hold for this.
I would really like your input before a major change like this.

[Outfenneced]

Go for it.

[Techcable]

@Outfenneced
Thanks