Need Help With Manipulating Kit Functions

Does anyone know how I would go about making specific functions for certain kits? For example how would I create a kit that when used when you fall you take less fall damage and you do out going damage to enemies around you. I have tried finding tutorials on youtube and have had no luck. Im just looking for a solution to creating kits with special abilities.

 

I'm assuming you're making a KitPvP server

Code:

public HashMap<Player, Kit> playerKits = new HashMap<Player, Kit>();

public void setKit (Player p, Kit kit) {
    playerKits.put(p, kit);
    p.getInventory().clear();
    p.getInventory().addItem(spiderSword);
}

public void entityDamageEvent(EntityDamageEvent event) {
    if(event.getEntity() instanceof Player) {
        Player p = (Player)event.getEntity();
        if(playerKits.containsKey(p) && playerKits.get(p).equals(Kit.SPIDER)) { // SPIDER kit takes less fall damage
            event.getCause().equals(DamageCause.FALL) {
                event.setDamage(event.getDamage()*0.25); // 75% Reduced Damage or 25% of the original damage
            }
        }
    }
}