Forum:Hundred Eyes Dragon

Hundred Eyes vs. Trishula
So Trishula, Dragon of the Ice Barrier is summoned to the field while Hundred Eyes Dragon is on the opposing side of the field. Can Hundred Eyes Dragon then use his graveyard monster removal in chain to Trishula's effect and remove a monster from the graveyard or would Trishula's effect activate first and remove a card from the opponent's graveyard before Hundred eyes can do anything?