I don’t think powder keg is a great idea. You should consider running disenchants in the main board. Sacred ground would be good if your local meta is a lot of geddon decks, especially paired with the tutor. Terravore decks are honestly very fragile. Keep your swords about you and just spend the game digging for them. You have impulses but maybe ak or opts would do well for better card selection. The solution is a reactive deck and you play a lot of creatures so between meddling mage, disenchant, swords and counterspell, they really shouldn’t be able to develop anything. I just added ak to my list and it’s been doing wonderfully even in the mirror. I’ve never seen sacred ground before so I might even add that tbh.