Equestrian Princess Celestia - Beast/Synchro-8/Light/Effect  
Summon Requirement: 1 “Equestrian” Tuner + 1 or more non-Tuner monsters  
Effect: This card can only be Synchro Summoned once per turn. Cannot be Tributed, and cannot be destroyed by card effects once per turn. If this card is Synchro Summoned: draw 1 card. If this card destroys an opponent’s monster by battle: gain LP equal to half the ATK of the destroyed monster. Once per End Phase; If this card is sent to the GY: Special Summon 1 “Equestrian Princess Luna” from your GY, also attach 2 “Equestrian” monsters from your hand or face-up on your field to it as XYZ material. (This is not considered an XYZ Summon.)
 
You can play this card freely on Duelingbook. I’ll even upload a few decklists that I’ve made just to get a basic feel of how the cards work. You’ll be able to change them to your liking.
 
Copyright for MLP:FIM belongs to Hasbro and Lauren Faust.  
Copyright of Yugioh belongs to Konami and Kazuki Takahashi.