, Pay 1 life: Add 
or 
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Mount Doom gives a black-red mana base three different jobs. It fixes either color at the cost of life, can chip away at every opponent, and offers a costly board wipe that preserves up to two chosen creatures. The last mode requires sacrificing the land and a legendary artifact, so it belongs in decks where those resources are realistically available.
The damage ability is useful when a single point matters more than its size suggests. Neheb, the Eternal counts life lost across opponents, while damage multipliers can increase the pressure. Activating it still consumes three mana and the land's tap, making it a supplemental outlet rather than efficient primary burn. Repeatedly using the colored mana ability also costs life, which can matter alongside black draw engines and other painful lands.
For the sweeper, a legendary artifact that has already provided value can become part of the payment. You choose up to two creatures to keep, then destroy the rest; the choice is not a targeted selection. Indestructible creatures can survive the destruction regardless of whether they were chosen. Plan the activation during your main phase and account for the lost land afterward. Mount Doom is most appealing when the ordinary fixing is already useful and the later wipe creates a credible recovery or finishing line, rather than requiring several otherwise unnecessary cards just to make that mode possible.
