Though they are of course curious as to the nature of the caverns and the politics of the surface world, they have no state-level designs on conquestthat is not to say, though, that there are not factions within the Oltec who could not be swayed toward conquest, should the right reason come along
1 Ketria Crystal
And, you're much more likely to find meta-adherent, efficient wins with Underworld BreachUnderworld Breach, Lion's Eye DiamondLion's Eye Diamond and Brain FreezeBrain Freeze in Bracket 5 than you are anywhere else
Stay healthy, and dont let your opponents resolve spells
Just remember that means you are committing to casting that Phyrexian Missionary for 2 mana if you dont have anything else on turn 2 as a 2/3 lifelink is a pretty decent creature
I hope this helps you clarify some questions, and be sure to check the discussion on MTG articles on the Draftsim Discord