Forum:The Fabled Unicore vs Stardust Dragon

The Fabled Unicore has the effect that while both players have the same amount of cards in hand you, the player, can negate the effect of a Spell, Trap, or Effect Monster's Effect, and destroy that card. My friend recently brought a huge discussion to ourselves in the sense of Stardust Dragon.

Stardust Dragon (if some of you don't know) negates the effect that destroys a card(s) on the field by tributing itself until the End Phase of that turn.

In sense, say the Fabled player has The Fabled Unicore out on the field, but the player has 4 cards in hand, while the opponent has 3 cards in hand. The Fabled player activates a spell card that the opponent does not like and has Horus Lv 8 on the field, and activates Horus' effect to destroy that spell card. The Fabled Unicore's effect would then chain to Horus, as both players now have 3 cards in hand, negating Horus and destroying Horus, the opponent then activates Stardust's effect to negate and destroy Unicore.

Would Unicore's effect also work on Stardust, as well as Horus due to the activation of effects, and these effects are not continuous, but activated.