Easy way killing legendaries battles pets

How easily beat legendaries pets and get red panda / achievment.

Legendaries battles pets own hard us pets. So it's take many try to make them down.
I found a easy way to destruct them with no effort.

Take a beattle with this attack : Apocalypse.
Some pet with 'invulnerable turn protection' like :

• When your pet is flying during one turn.
• When your pet is under-swimming or under-flooring.
• Repair.
• Survival.
• Undead pets. Rez one time.
• Mechanical pets. Rez with 20% life.
• Magics. Can get damaged more 40% lifes per turn.

And the great : - Phoenix. He rez full life =)

So in fact u have to do that.

1. Launch Apocalypse.
2. Change your beattle because (HE MUST BE ALIVE TO APOCALYPSE WORK).
3. Use some survival capacity or tanking pet. 
4. APOCALYPSE NOW !
5. Enjoy tiny cute red panda