I first added in some creatures which, like Halimar Tidecaller, would give me a bonus to my man-lands
On top of that, it reads: At the beginning of your next main phase, add an amount of colourless mana equal to that spells mana value." Basically, not only do you get to say no to something, you also get to cast something bigger on your next turn
Merry & Pippin are the best choice if you want to focus on the Food + Token aspect of the deck, as Pippin provides the Food that Merry needs to feed your growing army of creature tokens and then Pippin turns that into a hasty finisher
While its good in Mono-Red Aggro and Leyline in Standard, alongside playing well in explosive Commander decks, its hardly amazing everywhere
The deck is very fast and can get out of control very quickly if no one does anything to stop it