If you can eventually play this card's enchantment version, you can triple your mana output from your basic lands
Combined with an admittedly not-green Day of Judgement, or a similar board wipe, Heroic Intervention can allow you to swing in for the win
Let's say that we get the Saga in our graveyard with the help of Kruphix's Insight and Commune with the Gods (both of which also help us find our Starfield of Nyx)
As a result, Mentor of the Meek makes a perfect addition to token decks with mana to spare
Or is it on the weaker end of one mana draw cards in Cube, and maybe doesn't belong unless you have enough space?Replies Both Brainstorm and Stoneforge are prime examples of cards that are rather better outside of cube as you rightly point out
In a format where gusting effects like Counter Catcher are gone, this is a great advantage for picking off benched support like Fezandipiti ex (Shrouded Fable 38)