A Mysterious Contract - April 1st

1. "Can be unlucky": In many cultures, certain numbers carry bad luck. The most obvious candidate is 13, widely regarded as unlucky in Western tradition—think buildings skipping the 13th floor or superstitions around it.
2. "An awful supper guest": This likely nods to the Last Supper, where Judas Iscariot, the 13th guest (Jesus plus 12 apostles), betrayed Jesus, making 13 a symbol of treachery or ill fortune. An "awful" guest indeed!
3. "A lunar year": A lunar year typically has 12 months (based on the moon’s cycles, roughly 354 days), but in some contexts, it might imply a 13th month or cycle—like in lunisolar calendars (e.g., Chinese calendar) that occasionally add a leap month, making 13 total. This is a stretch, though; 13 more directly ties to the next clue.
4. "A Friday lost": This screams Friday the 13th, a day infamous for bad luck in Western culture. The "lost" could mean a day marked by misfortune or chaos, reinforcing 13 as the number.
5. "The number of your deaths": This is trickier. In a literal sense, you only die once, so it might mean "the number associated with death." In CrossFire, you can "die" multiple times in a match—could it be a kill/death count? But tying it to the prior clues, 13 fits as a symbolic "death number" due to its unlucky reputation.

So, the clues converge on 13. It’s unlucky, tied to a disastrous supper, linked to Friday the 13th, and poetically fits as a harbinger of "deaths."

"Deal out death, and death you take, for all of us must fall - 
From richest king to poorest pawn, from shortest to the tall!
Though you may go out, be sure to go out with a BOOM! 
And take with you, in the same way, those who would plot your doom!"

This hints at Search and Destroy - "Though you may go out, be sure to go out with a BOOM! 
And take with you, in the same way, those who would plot your doom!". Whether it is play 13 games of SnD or if you have to plant the bomb and wait for it to detonate i'm not sure, but that's my interpretation.

"From richest king to poorest pawn, from shortest to the tall" might just be there because it rhymes with the previous sentence.

"And when the explody boom is done,
When dust and smoke are clear as day,
All that's left is you and me, 
The Soldier and The Fae!"

This means that the speaker of this poem is the "Fae"

"Answer carefully, Mercenary!
The secret code at stake:
A balloon, a bomb, you and me - 
What sound do we all make?"

A balloon can make a boom sound, as well as a bomb. If we plant the bomb in SnD and wait for it to explode we also make the boom sound. The speaker of the poem (the Fae) also said "boom" multiple times in that poem so they too make that sound or say it. Thus i believe the answer to the riddle is "Boom", although you may also need to do some other task 13 times on top of answering the riddle.

EDIT: I just logged in and found 5 "Dragon Boat" crates. Not sure if they are from this event or not. All i did was answer the riddle and play about an hour of SnD. I didn't plant the bomb until it exploded or anything like that. If anyone knows more feel free to comment