Valanda would have preferred to get a Milliways door somewhere more convenient, but Milliways is still pretty useful even if he can only go in by himself right now. He heads in, takes a seat at Bar, and orders a plate of Hylian food.
"Griffith of Erlonn. I'm a druid, which means I can turn into a celestial smilodon and do assorted naturey things. If I may, what kinds of things do you make indestructible against what kinds of forces? I assume you couldn't, say, make an entire plane indestructible against the personal attention of an omnicidal deity."
"It's theoretically absolute, though I haven't tested it against a deity before. I do also have range and volume limits, and there's also specification issues – if I just make something fully indestructible, then it can't do anything, and looser specifications can pose issues against a determined and intelligent adversary. I could improve your armor, though?"
"Yes. It's a hard problem and I expect it to take thousands of years to solve, though if your protective enchantments are resistant to things like magically altering the truth value of their existence or can be used on truth values in general that would be the kind of thing that might be useful."