Golgari Persist: Green is really good at killing artifacts, and Golgari specifically offers unconditional removal like Assassin's Trophy and Abrupt Decay
Learn also brought the tactical play of sideboarding into the game itself, which added multiple new layers to both deckuilding and gameplay
Commander 2016 Tokens (TC16) #5 Common English Nonfoil
As mentioned before, Skyridge is already a very expensive set, being the last one printed by WOTC
If a permanent enchanted with an Aura that has totem armor would be destroyed by multiple state-based actions at the same time (most likely because a creature with deathtouch has dealt damage to that creature greater than or equal to its toughness) totem armor's effect will replace all of them and save the creature
So, if you pull an Energy card with lots of swirls, or some well-placed swirls in the background, make sure to put it in a sleeve straight away and post it on Reddit