Solution: The Giving Tree
Answer: HEARTDONOR

Written by Ethan

At first, the sentences seem to be nonsense, but each is a Printer's Devilry clue (clued by "missing" and "devilish"). Knowing that, the clues can still seem quite difficult to solve until one realizes that each of the inserted words is a winning word from a year of the National Spelling Bee (clued by "spell[ing]", Bougainvilleas, and 'bougainvillea' was one of the winning 2019 words). However, each of the inserted words has one letter missing. The correct words are in alphabetical order and have an enumeration to aid in identification. Identifying the missing letters and sorting them by the year of the winning word gives HEART DONOR.

Fixed clueCorrect wordYearMissing letter
They enTER A PYramid in Egypt, walking through the many chamberstHerapy1940H
The Danish writer LudVIG NETTed himself the title of the "founder of modern Danish and Norwegian literature".vignettE1952E
The musiC AT MARANhao is beautiful and is where singer Alcione Nazareth was born.catAmaran1959A
Find the areA, TO ONe decimal place, of the square.Ratoon1966R
On my sneakers, the VelCRO IS SANdy from the beach trip.croissanT1970T
My science teacher taught me this grammatically incorrect saying, "positivE IF I CATION, negative if I anion".Deification1978D
PerhaPS RIAS IS the girl who revives Issei in High School DxD.psOriasis1982O
The little FIB RAN Everywhere; what started as a small lie quickly grew into a larger problem.fibranNe1990N
Coca CoLA, DICE, ANd pens are items you might find on a desk.laOdicean2009O
Fidel CaSTRO, MUHammad Ali, and David Bowie all passed away in 2016.stromuhR2010R

Author’s Notes

I totally admit that some of these clues are... questionable at best. The earlier years were much easier to write since the words got harder over time (though there are some easier words like luge in 1984, then staphylococci 3 years later), but I'm glad that I was able to get a somewhat coherent sentence for all the words in the end. DEIFICATION is especially bad though, not even being grammatically correct.

I really wanted to include Spelling Bee winning words in a puzzle, and though this puzzle somewhat "works", I think there could've been better options. Our first team we testsolved on, Please Clap, solved the entire puzzle without realizing the Spelling Bee theme, leaving them quite confused on why we would ever clue a word such as LAODICEAN or STROMUHR. We ended up bolding the word "spell" to further clue it, which seemed to be successful in later testsolves. Based on the guess data though, I can't really tell how successful this was in practice though. When answering hints, we often advised teams to google some of the words they found to help them find the theme. STROMUHR, arguably the easiest clue, is a relatively rare word and looking in Google Images shows results of 2010 Spelling Bee.

After writing this puzzle, I feel like I'm much more aware of the Spelling Bee words in the wild. A couple weeks ago, I saw a catamaran and instantly took a picture and sent it to Vinhan. I've also found gladioli, plastic bougainvilleas, croissants, condominiums, chihuahuas, fibranne, cymotrichous hair, among other words. One day, I hope to see a stromuhr in real life :)

Another Printer's Devilry puzzle is UMD's Delightfully Devilish, which I really enjoyed solving!