The first part of the puzzle is a pure setting task, which is aided quite a bit by appropriate programming. One method for solving the task is: download the wordlist; reduce it to all 5-letter words; add all reversals of those 5-letter words; add the set of 6-letter words that are the 5-letter words with the alphabet-sum character appended; remove all 5-letter words that have repeated letters; and use a crossword grid filler (such as the free one called Qxw, available online), to fill a grid that looks like this:
?????? ?????? ?????? ?????? ?????? ?????-
Solvers can either (1) keep trying to fill until the 5-letter words to the right and bottom contain 10 different letters; (2) try a pattern like ?OILY on the right, which can start with D, R, or S, and leaves a lot of good letters for the 5-letter word on the bottom, which should yield a valid result quicker than simply proceeding at random; or (3) separate the wordlist (described above) into 2 lists, one where the 6-letter entries end with one set of 13 letters, and one where the 6-letter entries end with a letter from the complement of that set—then fill the acrosses from one list and the downs from the other list (Qxw and some other commercial programs allow this), ensuring a fill with 10-different letters to the right and bottom.
When solvers submit a string of 25 letters, it is checked by program, and if it meets all the rules, solvers receive part 2 of the puzzle. One string that works is: ARECAGAVELIMIDEOITARSEERT.
The second part of the puzzle consists of 10 clues to a cryptic double-square puzzle with 17 bigrams underneath.
The solutions to the cryptic clues are:
|Barrage used regularly to lock horns||bArRaGe UsEd||ARGUE|
|Bores fragment of glass counter with opening in glass for pathway, essentially||SHARD< with G for H||DRAGS|
|Bunch of trees presented a turning to red and orange||GAVE with A becoming RO||GROVE|
|Female fish has sympathy||F + EELS||FEELS|
|Gala lacks source of snacks like cheeses||FEST - S + AS||FETAS|
|Gullible deviant returned without clothing||dEVIANt<||NAIVE|
|Mountain range located past river country||R + URAL||RURAL|
|Russia's leader, following article, understood language||A + R + GOT||ARGOT|
|Some rude answers, more than one notable at school||ruDE ANSwers||DEANS|
|Spirit mostly added in to season marble||GIn in AGE||AGGIE|
The solution to the double-square is (words can read forwards or backwards):
Along with the puzzle, solvers are given a set of bigrams corresponding to the above coordinates 20-57-61-48-19-05-39-82-10-85-58-94-83-72-93-16-71 except instead of pairs of digits they are given pairs of letters. Those letters correspond to the two 5-letter right and bottom words that solvers submitted in the Part 1 task—which were constrained to be 10 different letters, so they can act unambiguously as a coordinate system.
Solvers will use the provided bigrams to extract letters from the Double Word Square of part 2, using the coordinate system they unwittingly provided in part 1, to get LAD ON FIRST TV GUIDE and that uniquely identifies DESI ARNAZ JR (to be entered in this fashion, per the instruction that the form of the answer must be the title of a Wikipedia article).