Spark Double is one of the only clones that works well with planeswalkers
Finally, all prices will be from the cheapest available printing, so long as that version is still of mythic rarity
If you can keep a steady supply of cards in hand, you can answer almost anything your opponent can throw at you
Either way, Hyldas doing some work while you're tapping your opponents creatures, and just making a 4/4 elemental creature each time already goes a long way
For just six mana (three generic, two black, and one green) you get 18 power
Creatures (26) 2 Verdurous Gearhulk 4 Voltaic Brawler 4 Lathnu Hellion 4 Bristling Hydra 4 Electrostatic Pummeler 4 Servant of the Conduit 4 Sage of Shaila's Claim Lands (20) Spells (14) Voltaic Brawler and Lathnu Hellion are great cards and great sources of Energy