I've never really been a fan of
Earthquake effects as my mass removal, and
Molten Disaster is no exception - they require a lot of mana to kill big things, miss flyers, and deal damage to yourself (making them worse in the less aggressive decks I tend to play). That said, there are certainly ways to take advantage of them. One of the more straightforward methods is to make use of a commander that synergizes with spell damage, such as
Gisela, Blade of Goldnight or
Torbran, Thane of Red Fell - if you increase the damage the spell deals, it requires a lot less mana for it to function as a board wipe. Simultaneously, if you're more aggressive, it can function as a way to close out a game by pressuring your opponents' life totals. You can also just run flyers to take advantage of that asymmetric aspect.
For Molten Disaster in particular, you're paying a bit of a premium for the ability to grant it split second, which is an extremely unique effect - it's great for fighting through countermagic and sac outlets. It's particularly good on a big X burn spell because you're likely to be spending a lot of mana on it, so getting it countered would be a massive tempo loss. Simultaneously, burning out a control player and giving them no window to respond seems extremely satisfying.
....I value the instant speed of stuff like
Starstorm and
Magmaquake higher than Molten Disaster's split second, and I also favor the efficiency of
Chain Reaction and
Blasphemous Act. Still, if you're planning to burn your opponents out, Molten Disaster seems like an excellent way to do so. Could also be a good meta call if you're facing lots of countermagic.
