That simultaneously makes Teysa both perfectly efficient on offense and perfectly efficient on defense
Similarly, if a red and white spell's effect causes it to deal damage to one thing and then deal more damage with a second instance of the word "deals," Firesong and Sunspeaker's last ability triggers twice, and so on
Joint Exploration takes this idea step further, giving you the choice of an instant speed Preordain for 2 mana (which while inefficient, lets you look at up to 3 new cards), or for the addition of a green mana, staple on Growth Spirals ability to drop another land onto the battlefield a package deal that is well worth the cost of admission
The King
In my opinion, it is a strong choice in the current meta, as it has fantastic matchups against 3 out of the top 5 decks and then plays about even with the other two
Badlands Badlands is an awesome mana source for Grixis commanders with penchant for control like pirate commander Admiral Beckett Brass and Lord Xander, the Collector