Magical Dimension

[NeoAqua777]

Ok I have a question about

Magical Dimension I understand that the offering part is not a cost, same for the Summon I think. But If I don't to both or one, can I still Destroy a monster?

 

[Cropz]

you must tribute a monster in order to be able to summon a Spellcaster.
you must tribute a monster AND summon a Spellcaster in order to be able to destroy a monster.