Vaporeons Wash Out Ability allows them to move as much Energy as they want from Benched Pokemon onto the Active Pokemon, so you can easily transfer all Benched Energy onto your Active Palkia ex or Articuno ex and continue attacking
With a decline in combo and more options for aggro decks Vampiric Tutor has seen a drop in use but remains easier to include than Demonic Tutor
If a permanent on the battlefield has in its mana cost, X is 0 when determining its mana value
Cheap legendary creatures gain more and more appeal for Cube all the time, and theres something really exciting about a Cube where casting Turn 1 K-9, Mox Amber, and Emry, Lurker of the Loch is a potential opening
Gyome, Master Chef is a nice inclusion as a sought-after reprint, as is Nether Traitor, and there are essentially a bunch of great cards to slot into any deck with access to green, black, or both