Since the ability asks you to search a hidden zone for a card with particular characteristics, you always have the option to fail to find an appropriate card during the search.
(The personal knowledge of players that a library contains a certain card is irrelevant; the game doesn't know it.)
The ability will continue to do what it can, ignoring instructions that are impossible. In your example, you will still shuffle your library.
Your brother is correct.
Double Major creates a copy of a spell whose copiable characteristics does not include the legendary supertype. When that spell copy resolves, the token that enters the battlefield will likewise not have the legendary supertype in its copiable characteristics.
In this situation, you would end up with only 7 lands.
The former Blinkmoth Nexus will be named Augmenter Pugilist, be green, be 1/1, have trample, flying and the +5/+5 ability, and have the types Artifact Creature -- Blinkmoth.
Notably it will not have the Land type.
It is important to understand that the phrase "It's still a land." does not add the Land type to the affected object. That phrase has the same meaning as "in addition to its other types."
In this instance, a separate part of the rule strips the previous creature subtypes so only Blinkmoth remains.
An exception would be a land with another permanent type like artifact (Tree of Tales) but that would use up your chance to play an artifact from your graveyard.
With the release of Commander Legends, this is no longer correct. Muldrothra has received functional changes to her rule text. She no longer plays all permanent types, but rather explicitly plays a land and casts a card of each permanent type.
In the most common case, you cannot do what you propose.
Most such effects are similar to, "Target player sacrifices a creature."
In such a case, the choice of object to sacrifice is made while the spell or ability resolves. During this time, no player can take actions like sacrificing to pay for another spell or ability's cost.
In the much rarer case of an effect that reads similar to, "Choose target permanent. Its controller sacrifices it.", it's a different matter. That chosen object is locked in when the spell or ability is placed on the stack. Players are free to interact with the chosen object before the spell or ability resolves.
If they sacrifice 100 goblins I take 100 damage despite the dissipation field? The damage is applied all at once and not as separate 1 damage triggers?
There are 100 separate 1 damage triggers, but the abilities exist independently from their source. As long as they get all 100 Bombardment abilities on the stack before the first Field's ability resolves, the Bombardment abilities will get to eventually resolve despite the Bombardment permanent no longer being on the battlefield.
Also you may not be aware but there is an ability known as split second. You make ask for strategy advice concerning its use in other parts of these forums.
701.15c If cards in a player’s library are shuffled or otherwise reordered, any revealed cards that are reordered stop being revealed and become new objects.
You can actually both sacrifice Wort to the Evolution's additional cost and conspire. Both the sacrifice and the tapping are additional costs, and different costs can be paid in any order, so during the casting process, you can first tap Wort and conspire, then sacrifice her. The conspire triggered ability will be put on the stack and give you a copy with 6 as the information for the sacrificed creature's CMC.
Am I missing something here?
From Wort's gatherer page:
3/14/2017
Some spells instruct you to sacrifice a creature as an additional cost to cast that spell. If you sacrifice Wort to pay that cost, that spell won’t have conspire at the moment it becomes cast, so conspire won’t trigger, even if you tapped two creatures.
1
(The personal knowledge of players that a library contains a certain card is irrelevant; the game doesn't know it.)
The ability will continue to do what it can, ignoring instructions that are impossible. In your example, you will still shuffle your library.
1
Your brother is correct.
Double Major creates a copy of a spell whose copiable characteristics does not include the legendary supertype. When that spell copy resolves, the token that enters the battlefield will likewise not have the legendary supertype in its copiable characteristics.
1
The former Blinkmoth Nexus will be named Augmenter Pugilist, be green, be 1/1, have trample, flying and the +5/+5 ability, and have the types Artifact Creature -- Blinkmoth.
Notably it will not have the Land type.
It is important to understand that the phrase "It's still a land." does not add the Land type to the affected object. That phrase has the same meaning as "in addition to its other types."
In this instance, a separate part of the rule strips the previous creature subtypes so only Blinkmoth remains.
1
With the release of Commander Legends, this is no longer correct. Muldrothra has received functional changes to her rule text. She no longer plays all permanent types, but rather explicitly plays a land and casts a card of each permanent type.
1
Most such effects are similar to, "Target player sacrifices a creature."
In such a case, the choice of object to sacrifice is made while the spell or ability resolves. During this time, no player can take actions like sacrificing to pay for another spell or ability's cost.
In the much rarer case of an effect that reads similar to, "Choose target permanent. Its controller sacrifices it.", it's a different matter. That chosen object is locked in when the spell or ability is placed on the stack. Players are free to interact with the chosen object before the spell or ability resolves.
1
Currently tokens phase out and in just like permanents represented by cards (or by both tokens and cards in the case of merged permanents).
1
There are 100 separate 1 damage triggers, but the abilities exist independently from their source. As long as they get all 100 Bombardment abilities on the stack before the first Field's ability resolves, the Bombardment abilities will get to eventually resolve despite the Bombardment permanent no longer being on the battlefield.
Also you may not be aware but there is an ability known as split second. You make ask for strategy advice concerning its use in other parts of these forums.
1
701.15c If cards in a player’s library are shuffled or otherwise reordered, any revealed cards that are reordered stop being revealed and become new objects.
1
Am I missing something here?
From Wort's gatherer page:
1