Okay, we've finalized our list of twelve participants, so here are the matchups! They'll also be in the OP.
These were chosen completely at random. I assigned each participant a number and had an RNG produce random sequences. I paired the adjacent numbers together, and I generated sequences until I had four that did not repeat any matchups.
Round 1:
twosuitsluke vs. MoraWintersoul
Evermind vs. TAC
Sacul vs. Puppies_On_Acid
romdrums vs. HOF
Elite vs. Cyril
Buddyhunter1 vs. The Walrus
Round 2:
Puppies_On_Acid vs. TAC
romdrums vs. Evermind
twosuitsluke vs. Elite
The Walrus vs. Sacul
Cyril vs. HOF
Buddyhunter1 vs. MoraWintersoul
Round 3:
Cyril vs. romdrums
The Walrus vs. Puppies_On_Acid
Buddyhunter1 vs. TAC
Evermind vs. Elite
twosuitsluke vs. Sacul
MoraWintersoul vs. HOF
Round 4:
twosuitsluke vs. Cyril
Evermind vs. HOF
TAC vs. Elite
Sacul vs. Buddyhunter1
romdrums vs. The Walrus
Puppies_On_Acid vs. MoraWintersoul