Notes & Combos
I've decided to avoid Kewl Tune this event and picked up a synchro deck - I'd much rather play some wonky fusions or R.B./Striker link deck but I've had plenty of KT in my rated duels so decided to build a deck around Junk Speeder, Accel Synchro Stardust Dragon, Hyper Librarian and the powerfull searchers that lock you into synchro summoning.
The deck doesn't have bad matchups - you either combo off/have HTs to stop opponent from comboing off or go next. The list is not refined super well as I just breezed through the event and didn't have a need to adjust; that said x3 Tuning would work wonders in this deck however I do not own any copies of those. HTs ratios can be changed, some of them can be replaced by more gas. Superheavy engine worked well for me but it might have been a little bit of a cope to add it in, you can consider just going more into Junk/Stardust stuff instead. Adventure Engine has performed very well both as a source of omni and as a way to kickstart your synchro plays. Best of luck duelists!