The answer is The converted mana cost of a modal double-faced card is based on the characteristics of the face that's being considered
I am truly impressed at the card selection here: Rite of Passage works great with the fight spells youll add to the deck, Berserk is nullified by his regeneration, Ozolith is great in case of exile spells, and then Rhythm of the Wild, one of the best feelings in Magic is landing this early
So if you read my review of Charizard, you'll know that I thought it was an above average Basic Pokemon card and a solid starter type Pokemon for a fire type deck, I recommended using that card with 4 Burning Energy cards, thus allowing Charmander to do 30 damage every turn without having to add any additional energy cards to it
Similar to the Mox artifacts, Black Lotus costs zero mana, so you can play it on your first turn along side a land, but adds three mana of any one color when you sacrifice it