Playing the Overlord on three will put you at four lands that turn, and if you have another land drop on your fourth turn, you can cast another Overlord for the full five mana, as a creature this time, while further ramping you to six lands
Prior to rotation, The Pokmon Company International announces which sets cards will remain legal for the following year
I would not overreact to the perception of this set as "bad" and buy everything that isnt awful, but its safer than normal to preorder or trade for the significant cards in this set than it was for Return to Ravnica or Theros
1/Day Each: Meteor Swarm , Wall of Fire (9th level) 2/Day Each: Fireball (7th level), Lightning Bolt (7th level), Chain Lightning (7th level) 3/Day Each: Call Lightning (5th level), Melf's Minute Meteors (5th level), Agnazzars Scorcher (lightning damage) (5th level), Fire Storm (5th level) At Will: Fireball , Lightning Bolt , Chain Lightning , Thunderwave (3rd level) The Behemoth has advantage on saving throws against being charmed or stunned