Forum:Vennomniaga vs the fable unicore

I WOULD LIKE TO KNOW IF Vennominaga the Deity of Poisonous Snakes EFFECT IS NEGATED BY The Fabled Unicore WHEN VENNOMINAGA WAS ON THE FIELD FIRST. HER EFFECT CLEARLY SAYS " This card cannot be targeted by, and is unaffected by, Spell/Trap effects and other Effect Monsters' effects." BUT The Fabled Unicore SAYS While you and your opponent have the same number of cards in hand, negate all Spell, Trap and Effect Monster effects activated by your opponent, and destroy that Spell/Trap/Monster...... SO DOES THE UNICORE NEGATES MY MONSTER EFFECT MY MONSTER WAS SUMMONED FIRST?