Superheavy Samurai Battleball

If all monsters you control are "Superheavy Samurai" monsters, and you have no Spell/Trap Cards in your Graveyard: You can target 1 face-up monster your opponent controls; send both that opponent's monster and this card from the field to the Graveyard, then Special Summon 1 "Superheavy Samurai" Synchro Monster from your Extra Deck whose Level equals the total original Levels of the sent monsters. (This Special Summon is treated as a Synchro Summon.) You can only use this effect of "Superheavy Samurai Battleball" once per turn.