The only problem with Mount Doom is it costs life to make mana, so you don't really want to draw it early
Its always nice to see it show up in a Masters set or a flashback set, but you dont see it in Constructed formats as much anymore as there are just better options
with top competitive decks in other Eternal formats that top $1000, the urge to play a format where the top decks run less than $100 is nearly impossible to resist
If two creatures you control with +1/+1 counters on them become the target of the same spell or ability an opponent controls, Elrond, Master of Healing's last ability will trigger twice
Again, you can check out your commander's page to look for common card velocity effects
Pair it with something that removes -1/-1 counters or adds +1/+1 counters when it comes into play and a free sacrifice outlet like Ashnod's Altar and this creature goes infinite in so many ways