I'm certainly not the one to give you advice on Subterra, but I'll try anyway lol. Here's the deck I threw together to bring to Baku-Con:Coredem 750gPreyas II 720g/300gHyper Dragonoid 700gCrushing BlowCarpus CryptMana SurgeRock OnSoil ManaMasq. Throw(Shadow Lash)Not extremely thought out, but the general plan is to play Masq. Throw first, use Diablo on my card(Crushing Blow), then use Coredem+Rock On(Soil Mana if required) on their card, then Hyper on my card(Mana Surge), then if I haven't won yet use Coredem+Shadow Lash+Soil Mana(if I still have it) on their card.Hope that helps even slightly lol.
I don't think we can use GI bakugan...
You actually can, I brawled somebody who had one and he even double-checked if he could use it and the "Battle Masters" said yes. Obviously you can't use the new cards, but other than that you can use GIs.