The Motherlode, Excavator

If an effect says you get one or more {E}, you get that many energy counters. To pay one or more {E}, you lose that many energy counters. You can't pay more energy counters than you have. Any effects that interact with counters a player gets, has, or loses can interact with energy counters.

Some spells and abilities that give you {E} may require targets. If each target chosen is an illegal target as that spell or ability tries to resolve, it won't resolve. You won't get any {E}.

Energy counters are a kind of counter that a player may have. They're not associated with any specific permanents.

Some triggered abilities that state that you "may pay" a certain amount of {E} describe an effect that happens "If you do." In that case, no player may take actions to try to stop the ability's effect after you make your choice. If the payment is followed by the phrase "When you do," then you'll choose any targets for that reflexive triggered ability and put it on the stack before players can take actions.

The Motherlode's reflexive triggered ability prevents all creatures without flying that player controls from blocking that turn, including creatures that lose flying after the ability resolves as well as creatures without flying that enter the battlefield or come under that player's control later in the turn.

Use the number of nonbasic lands the target opponent controls when The Motherlode's first ability resolves to determine the number of energy counters you get.

You don't choose a target nonbasic land at the time The Motherlode's last ability triggers. Rather, a second "reflexive" ability triggers when you pay {E}{E}{E}{E} this way. You choose a target for that ability as it goes on the stack. Each player may respond to this triggered ability as normal.

Keep track of how many energy counters each player has. Potential ways to track this include writing them down on paper or using dice, but any method that is clear and mutually agreeable is fine. (At higher levels of tournament play, dice may not be allowed for tracking counters that players have.)

If the target nonbasic land is an illegal target as The Motherlode's reflexive triggered ability tries to resolve, it won't resolve and none of its effects happen. Creatures defending player controls without flying will still be able to block this turn.