mtg commander counterspell deck The 34 Best Counterspells of All Time in Magic Ranked allowing you to counter any Mtg Counterspell Bundle - Etsy

Being such a synergy based deck you are absolutely best off going into extra colours so as to get the most suitable card pairings with the highest base power you can manage

When Grothama leaves the battlefield, each player draws cards equal to the amount of damage dealt to Grothama this turn by sources they controlled

Krosan Drover

Verdant Catacombs: search for a Swamp or Forest

PYRE OF HEROES Speaking of Avacyn, Angel of Hope, and Serra Emissary for that matter how do you reliably fish them out of your deck

Decklists You could get inspired by looking at other Commander players MTG decklists on places like TCGPlayer