To determine the total cost of a spell, start with the mana cost or alternative cost you're paying, add any cost increases, then apply any cost reductions (such as that of Saheeli's second ability)
Sphinx of the Revelation Im not sure how often the lifegain stuff works in most energy decks, but if you just drop this sphinx in a lifegain deck, itll net you a lot of energy and then can tap to use it to draw loads of cards
Scavenger, an upgrade to Vampire Nighthawk, seems like a great stall against aggressive strategies and a late-game finisher that helps regain your life total
When you activate it, you draw a card and then take your Ante card and place it into your graveyard, swapping it with Jeweled Bird
If you actually have the Arabian Nights version of this card, please do not play it, as Juzam Djinns value comes from its rarity
It used to be banned in Modern, but its playable now (and hasn't broken anything just yet)