onPlayerDeath

@SubscribeEvent
    public void onPlayerDeath(LivingDeathEvent event) {
        Entity entity = event.getEntity();

        if (entity instanceof PlayerEntity) {
            PlayerEntity player = (PlayerEntity)entity;

            for (ServerPlayerEntity serverPlayerEntity : player.getServer().getPlayerList().getPlayers()) {

                if (player.getCapability(BindingCapabilities.LIFE_BOUND_CAPABILITY).orElse(null).isBound()) {
                    IBoundCapability bound = player.getCapability(BindingCapabilities.LIFE_BOUND_CAPABILITY).orElse(null);

                    if (event.getSource() == ModDamageSource.causeBoundPlayer(player)) {
                        BoundPlayersList.removeUsername(bound.getUUID());
                    } else {
                        BoundPlayersList.setUsername(bound.getUUID(), bound.getName());
                    }

                    if (!player.world.isRemote) {
                        /** Adds potion effect to bound player. */
                        serverPlayerEntity.addPotionEffect(new EffectInstance(LifeBindingPotion.LIFE_DAMAGING_EFFECT.get(), 300));
                        /** Removes potion from player who had died/triggered the event. */
                        player.removePotionEffect(LifeBindingPotion.LIFE_DAMAGING_EFFECT.get());
                    }
                }
            }
        }
    }