English.&Nbsp
Exerting a card means turning it 90 degrees to its side
When you tap it, you add X mana of any one color, where X is the greatest number of creatures you control that have a creature type in common
Just look at Bloomburrow and Duskmourn, with their exclusive Anime and Japan Showcase cards
The value of X is calculated only once, as Explosive Prodigy's ability resolves
I also run ramp spells like Three Visits (thank god for reprints), Nature's Lore, Skyshroud Claim, Smothering Tithe, The Great Henge (which costs only two mana when Sliver Overlord, Sliver Legion, Sliver Queen, or The First Sliver are out), and 'rocks' like Mana Crypt, Sol Ring, Arcane Signet, and Chromatic Lantern which can't help cast the Sliver lords, but CAN help cast Morophon, the Boundless or pay for Sliver Overlord's tutor