Haste Yellow Rush [Seifer Open 1, 3rd place]
On ladder, this deck is 19-5. In the tournament, it was 1-2 (one win, two losses).
It's weak against mono-green (especially Living Willow) and against the type of rush that uses large creatures. I initially started playing it to counter Crackthorn/Salamander GR and Gemshell BR, which blue jump struggles against.
The other decks I brought to the Seifer Open 1 are:
• the Blue Jump list that Sunekichi brought to the Khalim Open 5 https://www.faeria.com/the-hub/deck/4023-khalim-open-5-blue-jump (After playing it for over 120 games on ladder, I couldn't find a single thing I wanted to change about it. In this tournament, it went 11-2. Huge thanks to Sunekichi for posting it.)
• a RY anti-swarm deck already on the hub at https://www.faeria.com/the-hub/deck/4019-anti-swarm-ry-events
• a BG beast deck that went 0-1. (Humbling Vision apparently does have a land requirement, which is something I rediscovered the hard way after playing Blue Jump all day.)