Only one way to find out, and that's to do what we always do on Innistrad: ignore the consequences and charge right into the darkness with no regard for personal safety or preparation whatsoever and why are you thinking let's just go Day & Night, Daybound & Nightbound Not everything on Innistrad is as it seems
Technically Sylvan Library also draws cards, but at an unfortunately steep price
And that just makes this Donald too slow to be useful, I think
they check that edges are sharp and free from whitening
If Gluttonous Hellkite is countered or otherwise leaves the stack in response to that triggered ability, the triggered ability will still resolve as normal
Koth Red type decks that want to do mountain shenanigans will probably like this, and Gruul Lands decks will make use of an extra landfall trigger reasonably well, but yeah I'm not super stoked (ha!) about this guy in general