Hurl (Yellow)

As an additional cost to play this, you may pay

.

If the additional cost is paid, this gets "When this attacks, target dagger you control deals 1 damage to target hero. If damage is dealt this way, the dagger has hit. Destroy the dagger."

Go again

Rulings

From the Outsiders release notes

This is a targeted effect on an attack-trigger. The dagger must be under your control when the triggered effect is added to the stack. If you do not control a dagger this triggered effect does not get added to the stack (it does not resolve).
If damage is dealt, it is considered a “hit event” with the dagger considered to have hit.
The dagger itself is not an attack.
If the dagger hits this way, the attack on the active chain link is not considered to have hit. This is relevant for effects that are conditional only on the attack hitting (Benji, on-hit effects on the attack etc.)
If the dagger hits this way, the active chain link (but not the attack) is considered to have hit. This is relevant for effects that are conditional on a chain link hitting instead of an attack hitting (e.g. Mask of Momentum, Whirling Mist Blossom, etc.)
The dagger is destroyed regardless of whether it hits.
When the dagger is destroyed, it is put into the graveyard. It is neither put into your inventory nor continues to exist in the arena.
If both a dagger deals damage due to these effects and an attack hits in the damage step in the same active chain link, this situation does not count as two separate chain links hitting. A chain link simply hits or it doesn’t.

Keyword notes

Go again - Go again allows multiple actions to be played in a turn when usually playing an action with use up your action point, and therefore end your turn. A card with go again gives the controller of that card or activated ability 1 action point when it resolves.

When an action with go again resolves, its controller gains 1 action point.
Multiple instances of go again on the same card or activated ability do not stack. If a card or activated ability has multiple instances of go again when it resolves its controller gains 1 action point only.
If an action with go again does not resolve, its controller does not gain 1 action point.
You cannot reveal a card with no to Belittle. The card must have a value to its power that is 3 or less. (0 is a value)