It perhaps doesn't help that Zacian and Zamazenta never really resonated with many collectors when it comes to Legendary Pokemon
Include a classic Death and Taxes theme to make things difficult for your opponents, and you should be able to get the most out of Ardenn and Rebbec very quickly
Don't apply Weakness and Resistance
Realms and Relics Box Toppers This set has a selection of 30 lands and artifacts that are all desired reprints, going from important lands like Urborg, Tomb of Yawgmoth, Karakas, and Cavern of Souls to staple artifacts like The Great Henge, Shadowspear, and Ensnaring Bridge
Heartless Act Heartless Act is a cheap removal spell with some restrictions
Playing cards which can self-sacrifice or cycle wherever possible is a solid start and is usually a sidegrade at worst the precon already features several strong options in this vein