We are confused with the wording.
"When performing an attack targeting a hexed monster, a hero may discard any number of hex tokens before spending surge . The attack gains +1 damage for each hex token discarded."

The question is, does the bold section mean a.) you must spend a surge to get the attack +1, or b.) it is free, but takes place before the spend surge step of the attack.

If a.), then do you have to spend more than one surge to discard more than one hex? (I assume this is moot, as I read b.) to be correct).

Before spending surges:

As in, after the attack has been determined to be a hit (and not a miss), but before the hero spends his surges, he can decide to discard hexes to add damage. The time limitation is so that the hero can wait to determine if the attack hits (and not waste hexes on a miss) but also cannot just tack on extra damage at the end when the OL has no chance to counter with a card. So, "b."

EDIT: Unknown X has got it below. It's there to make it clear that you can't hex and then immediately discard that same hex token to add damage. In other words, damage added to an attack by discarding hex tokens can only be done with hex tokens that were already on the monster before the spend surges step.

This "before surges are spend" thing is mainly there to ensure that you cannot use the extra damage on the initial attack. Hex Tokens get placed through spending a surge, they must be used before surges are spent, thus explicitly excluding any chance of using tokens on the initial attack.

Spending hex tokens of course does not require any surges

I must confess I don't know what you mean by "initial attack." Enfeebling hex doesn't involve multiple attacks. Could you please clarify?

I guess Unknown X is referring to the attack used to initially hex the monster (using a surge on the Enfeebling Hex ability).
However, discarding a hex token in the attack that placed the hex token is not possible due to "When performing an attack targeting a hexed monster ..." as targeting is done in step 1 of the attack. We do not need that "before spending surges" for that.

I understand, now, thanks. That's probably the main reason for the inclusion of that time trigger.

22 hours ago, Sadgit said:

I guess Unknown X is referring to the attack used to initially hex the monster (using a surge on the Enfeebling Hex ability).
However, discarding a hex token in the attack that placed the hex token is not possible due to "When performing an attack targeting a hexed monster ..." as targeting is done in step 1 of the attack. We do not need that "before spending surges" for that.

I disagree there, for the same reason Frenzy, which reads " Play this card when activating a monster during your turn. That monster may perform an additional attack action this turn in addition to its normal 2 actions. " does not need to be played at the start of a monster's actviation.

It does not say "when you choose a hexed monster as the target of your attack", it says targeting, as opposed to an attack that just affects a monster (like monsters adjacent to the target for blast, etc.).

For example, plague cloud explicitly says " Perform an attack with a Magic weapon. This attack targets each hexed monster in your line of sight and ignores range. Each figure rolls defense dice separately. Before rolling dice for the attack, each monster adjacent to you is hexed. " to be in accord with this.

I do not get your Plague Cloud example but I in essence we both agree.