In my example, Y'shtola, Night's Blessed is a great commander to maximize my use of Toxic Deluge, so in the Deck Filters area, I started typing the card name, it popped up so I selected the card and clicked the + button to the right and now the green box below it tells me the decks I view will include Toxic Deluge
But if I had to choose one from a competitive-oriented point of view, Id definitely go for Vampiric Bloodline
The new twist on hybrid was something we dubbed "twobrid," where you had a choice between paying a mana of a certain color or two generic mana
Any creature coming into contact via blocking or attacking is immediately hit for 1 or 2 damage (depending on which side is currently active) and its amazing how many of your opponents will forget about this little detail during the heat of battle
Mirror Room // Fractured Realm Mirror Room adds a playable effect in many EDH decks that already play 3-mana clones like Glasspool Mimic