Omnath really loves lands, so team them up with anything that lets you play extra lands, plus other permanents with Landfall triggers, and its not hard to go-off, gaining an insurmountable value and mana advantage
The lands are Snow mainly for Coldsteel Heart, board wipe Dead of Winter and Iceberg Cancrix
You can Tribute this card with 3 Spell Counters on it
Most of the best candidates in my mind are individual creatures which convert accumulated resources (be they cards, treasures, or creatures in play) into direct damage to players
This meant that there were 4 total tournaments ran, resulting a total of 4 copies of each No.1-3 trainer card
Of course, when the marquee general is as prolific as Breya, it ultimately means that the back-up generals are going to be a little less notable within the context of their product