public void PerformAttack(int attackIndex)
    {
        if (glorten.ReadyToAttack)
        {
            int[] damages = glorten.PerformAttack(attackIndex);
            bossFight.currentAttackDamage = Random.Range(damages[0], damages[1] + 1);

            //special cases
            switch (attackIndex)
            {
            case 0:
                //normal attack
                Vector3 attackBossPosition = new Vector3(glorten.transform.localPosition.x, glorten.transform.localPosition.y, 1.0f);
                //move
                Go.to(glorten.transform, 0.4f, new GoTweenConfig()
                      .localPosition(attackBossPosition)
                      .setEaseType(GoEaseType.Linear)
                      .setIterations(2, GoLoopType.PingPong)
                      .onIterationEnd(tween => {
                    if (tween.completedIterations < 2)
                    {
                        bossFight.DamageBoss(null);
                    }
                }
                                      )
                      .onComplete(bossFight.ChangeTurn));
                break;

            case 1:
                //heal
                Transform healSpell = glorten.transform.Find("HealSpell");

                //make decal appear
                Transform Decal = healSpell.Find("Decal");
                if (Decal != null)
                {
                    SpriteRenderer sr = Decal.gameObject.GetComponent <SpriteRenderer>();
                    sr.color = new Color(1.0f, 1.0f, 1.0f, 0.0f);
                    sr.transform.localScale = new Vector3(0.4f, 0.4f, 1.0f);
                    Go.to(sr, 5.0f, new GoTweenConfig()
                          .colorProp("color", new Vector4(1.0f, 1.0f, 1.0f, 1.0f))
                          .setEaseType(GoEaseType.SineOut)
                          .onComplete(tween =>
                    {
                        Go.to(sr, 0.5f, new GoTweenConfig()
                              .colorProp("color", new Vector4(1.0f, 1.0f, 1.0f, 0.0f))
                              .setEaseType(GoEaseType.SineIn)
                              );

                        Go.to(sr.transform, 0.5f, new GoTweenConfig()
                              .scale(new Vector3(0.1f, 0.1f, 1.0f))
                              .setEaseType(GoEaseType.SineIn)
                              );

                        bossFight.HealPlayer(null);
                        bossFight.ChangeTurn(null);
                    })
                          );
                }

                //launch particles
                ParticleSystem[] particles = healSpell.GetComponentsInChildren <ParticleSystem>();
                foreach (ParticleSystem ps in particles)
                {
                    ps.Play();
                }

                //rotate whole group
                healSpell.localScale = new Vector3(0.6f, 1.0f, 0.6f);
                Go.to(healSpell, 5.0f, new GoTweenConfig()
                      .localRotation(new Vector3(0, 1440f, 0), true)
                      .scale(1.0f)
                      .setEaseType(GoEaseType.Linear));

                break;

            case 2:
                //fire attack
                Transform fireSpell = glorten.transform.Find("FireSpell");
                //rotate fireSpell
                Go.to(fireSpell, 10.0f, new GoTweenConfig()
                      .localRotation(new Vector3(0, 1440f, 0), true)
                      .scale(1.0f)
                      .setEaseType(GoEaseType.Linear));

                //make decal appear
                Transform fireDecal = fireSpell.Find("Decal");
                if (fireDecal != null)
                {
                    SpriteRenderer sr = fireDecal.gameObject.GetComponent <SpriteRenderer>();
                    sr.color = new Color(1.0f, 1.0f, 1.0f, 0.0f);
                    sr.transform.localScale = new Vector3(0.4f, 0.4f, 0.4f);
                    Go.to(sr, 10.0f, new GoTweenConfig()
                          .colorProp("color", new Vector4(1.0f, 1.0f, 1.0f, 1.0f))
                          .setEaseType(GoEaseType.SineOut)
                          .onComplete(tween =>
                    {
                        Go.to(sr, 0.5f, new GoTweenConfig()
                              .colorProp("color", new Vector4(1.0f, 1.0f, 1.0f, 0.0f))
                              .setEaseType(GoEaseType.SineIn)
                              );

                        Go.to(sr.transform, 0.5f, new GoTweenConfig()
                              .scale(new Vector3(0.1f, 0.1f, 1.0f))
                              .setEaseType(GoEaseType.SineIn)
                              .onComplete(bossFight.ChangeTurn)
                              );
                    })
                          );
                }

                //launch particles
                ParticleSystem[] fireParticles = fireSpell.GetComponentsInChildren <ParticleSystem>();
                foreach (ParticleSystem ps in fireParticles)
                {
                    ps.Play();
                }

                int fireball1Damage = (bossFight.currentAttackDamage / 7) * 1;
                int fireball2Damage = (bossFight.currentAttackDamage / 7) * 2;
                int fireball3Damage = (bossFight.currentAttackDamage / 7) * 4;

                //fireball1
                Transform fireBall1 = fireSpell.Find("FireBall1");
                fireBall1.localPosition = new Vector3(0.0f, fireBall1.localPosition.y, 0.0f);
                GoTween fb1tw = new GoTween(fireBall1, 1.0f, new GoTweenConfig()
                                            .position(new Vector3(0, 0, 5f), true)
                                            .setEaseType(GoEaseType.Linear)
                                            .onComplete(tweenfb1 =>
                {
                    bossFight.currentAttackDamage = fireball1Damage;
                    bossFight.DamageBoss(null);
                }));
                //fireball2
                Transform fireBall2 = fireSpell.Find("FireBall2");
                fireBall2.localPosition = new Vector3(0.0f, fireBall2.localPosition.y, 0.0f);
                GoTween fb2tw = new GoTween(fireBall2, 1.0f, new GoTweenConfig()
                                            .position(new Vector3(0, 0, 5f), true)
                                            .setEaseType(GoEaseType.Linear)
                                            .onComplete(tweenfb2 =>
                {
                    bossFight.currentAttackDamage = fireball2Damage;
                    bossFight.DamageBoss(null);
                }));

                //fireball3
                Transform fireBall3 = fireSpell.Find("FireBall3");
                fireBall3.localPosition = new Vector3(0.0f, fireBall3.localPosition.y, 0.0f);
                GoTween fb3tw = new GoTween(fireBall3, 1.0f, new GoTweenConfig()
                                            .position(new Vector3(0, 0, 5f), true)
                                            .setEaseType(GoEaseType.Linear)
                                            .onComplete(tweenfb3 =>
                {
                    bossFight.currentAttackDamage = fireball3Damage;
                    bossFight.DamageBossBig(null);
                }));

                GoTweenChain chain = new GoTweenChain();
                chain.appendDelay(3f).append(fb1tw).appendDelay(0.5f).append(fb2tw).appendDelay(0.3f).append(fb3tw);
                chain.play();

                break;

            case 3:
                //hearthquake
                Transform earthSpell = glorten.transform.Find("EarthSpell");
                //rotate spell
                Go.to(earthSpell, 9.0f, new GoTweenConfig()
                      .localRotation(new Vector3(0, 1440f, 0), true)
                      .scale(1.0f)
                      .setEaseType(GoEaseType.Linear));

                //make decal appear
                Transform earthDecal = earthSpell.Find("Decal");
                if (earthDecal != null)
                {
                    SpriteRenderer sr = earthDecal.gameObject.GetComponent <SpriteRenderer>();
                    sr.color = new Color(1.0f, 1.0f, 1.0f, 0.0f);
                    sr.transform.localScale = new Vector3(0.4f, 0.4f, 0.4f);
                    Go.to(sr, 9.0f, new GoTweenConfig()
                          .colorProp("color", new Vector4(1.0f, 1.0f, 1.0f, 1.0f))
                          .setEaseType(GoEaseType.SineOut)
                          .onComplete(tween =>
                    {
                        Go.to(sr, 0.5f, new GoTweenConfig()
                              .colorProp("color", new Vector4(1.0f, 1.0f, 1.0f, 0.0f))
                              .setEaseType(GoEaseType.SineIn)
                              );

                        Go.to(sr.transform, 0.5f, new GoTweenConfig()
                              .scale(new Vector3(0.1f, 0.1f, 1.0f))
                              .setEaseType(GoEaseType.SineIn)
                              .onComplete(bossFight.ChangeTurn)
                              );
                    })
                          );
                }

                //launch particles
                ParticleSystem[] earthParticles = earthSpell.GetComponentsInChildren <ParticleSystem>();
                foreach (ParticleSystem ps in earthParticles)
                {
                    ps.Play();
                }

                //earthquake rocks
                Transform movingRocks = earthSpell.Find("MovingRocks");
                movingRocks.localPosition = new Vector3(0.0f, 0.0f, 1.56f);
                Go.to(movingRocks, 1.0f, new GoTweenConfig()
                      .position(new Vector3(0, 0, 5f), true)
                      .setEaseType(GoEaseType.Linear)
                      .setDelay(5.0f)
                      .onComplete(bossFight.DamageBossBig));

                break;
            }
        }
    }