mtg cards like keen sense | Planar Chaos - Japanese Enchant creature Whenever enchanted creature deals damage to an opponent Keen Sense (Card) | EDHREC

Promo winner cards are given out at these, starting with Stitch Rock Star Championship Promo

Cabal CoffersCabal Coffers isn't exactly a new card itself, and neither are several of the black mana-doublers, so getting to the point where you could afford to repeatedly pay Kokusho's commander tax and immediately sacrifice it to a Phyrexian PlaguelordPhyrexian Plaguelord wasn't difficult

To decide what colors you will be playing, you'll want to look for massive threats

Nykthos, Shrine to Nyx can generate absurd amounts of mana, especially if your deck is base green which most hydras are

Shes already a pretty great mana dork in the command zone for a +1/+1 strategy