This got hit by the frost this spring. It's growing in full sun, but generally just looks sick. The second flush of leaves are looking like this:
What do the backsides of the leaves look like?
Here's the backside of a leaf:
Here's another shot:
That kind of looks like what's on my Cathedral Windows. The "guys" said they thought it was sun and stress.
Is there a bit of a mosaic pattern on some of the leaves or am I seeing things? I'm wondering if your hosta might be infected with impatiens necrotic spot virus which might explain the dead spotting. The dying edges could be from under-watering or over-watering. I don't think this is the same thing as the Cathedral Windows. I think the Cathedral Windows is just heat/drying damage - maybe there was an especially hot, dry wind one day that did a little damage there some time back and it is just now turning brown.
Sorry, but something doesn't look right with that Krossa Regal.