Honorblade questions

[XaviGzz]

Using the following quote from Syl about honorblades:
"This sword gave the assassin power to use lashings, but it also fed upon his Stormlight. A person who uses this will need far, far more Light than you will. Dangerous levels of it." 

From what I understand, this would mean that the honorblade is consuming the stormlight, same as Nightblood, to do what they do, in Honorblades case: grant the surges to the wielder. 

This led me to a couple of questions:
Can the honorblades be feed any kind of investiture, or are they tied to stormlight? (ex. Can a fused use voidlight to fuel an honorblade?)

If Breaths can be used to power an Honorblade, could Returned kill themselves using one?

And the additional, but maybe it's more related to the nature of Heralds, how did the Heralds get access to stormlight to continuously power their blades, did they really depend on gems? Or can Heralds produce stormlight as part of their perks package? (If I remember correctly Lift mentions that Nale starts glowing suddenly in one of her Interludes)

[Frustration he/him]

So the Honorblades themselves don't require stromlight, just that preforming surgebinding with them requires more light than Radiants do.

In theory they could be hacked to use other investiture sources, but I don't think they would naturally use them.

Heralds had access to stormlight from Honor but after he died they no longer have that.