Forum:Can stardust assault mode negate a nomi card?

alright so i was dueling my friend and he had a face up stardust assault mode and i have 3 crsytal beasts in my spell/trap zone and i give them up to bring out hamon and he tried to negate the summoning but what im saying is that its a summon condition not an effect and this duels at a standstill any help?