Intro

This is my Zaxara, the Exemplary deck. While a lot of Zaxara decks include many hydras, this deck focuses on casting a lot of non-creature spells, then using Zaxara's triggered ability to make creatures. Having a 4-mana dork that taps for 2 colored mana enables us to cast some large spells very early, so this deck's plan is to ramp hard and cast big spells, then use the Hydra tokens to engage in combat. Because Zaxara is a mana dork, it's important that we cast it on turn 3 using 2-mana ramp. Then, we'll have 7 mana on turn 4, which enables us to cast large spells like Zendikar Resurgent, Gargos, Vicious Watcher, or even The Great Henge.

Lands

Since we need to cast Zaxara on turn 3, this deck includes mostly lands that can enter untapped. Specifically, it runs the Shocklands, painlands, 2 filterlands and 1 crowdland.

• Alchemist's Refuge: Flash is very useful, and we can generate enough mana that we can spare 3 to do so.
• Bojuka Bog: One of the best graveyard hate cards.
• Mosswort Bridge: This is in here because it's so easy to turn on. Be careful, though, because you can't put X-cost spells under it.
• Path of Ancestry: It enters tapped, but it can tap for any of our colors. We don't cast many Hydra spells, but it's still a nice effect when we do.
• Zagoth Triome: Again, can tap for any color. It can also cycle for 3 mana, but the main reason is that we can tutor it out with Farseek or Nature's Lore.

Artifacts

We run lots of 2-mana rocks to ramp into Zaxara, as well as staples like Sol Ring and Lightning Greaves.

• Shadowspear: This doesn't really synergize with the deck (although giving trample is nice), but the real value is its activated ability.
• The Great Henge: I do not like this card. I think it rewards players too much for something they were going to do anyway, for no cost. But, it's too good to not run.
• The Ozolith: A must-have for any deck with +1/+1 counters.
• Thran Dynamo: Since Zaxara taps for colored mana, this is usually better than its sibling, Gilded Lotus. Unless you need a lot of colored mana for some reason, it effectively just costs 1 mana the turn you play it. If we have 7 mana turn 4, we can cast this and Gargos, Vicious Watcher or Vigor (we're guaranteed to have at least three green mana; 2 from Zaxara and 1 that we used to cast it).

Enchantments

• Retribution of the Ancients: Once we have some big Hydra tokens, this becomes a very powerful and repeatable source of creature removal.
• Unbound Flourishing: A must-have for this deck, since we have so many X-cost spells. It will also make our Hydra tokens bigger when we cast an X-cost permanent.

Instants

• Biomass Mutation: For our tokens, their new power and toughness will be X plus however many counters they had, making them very large.
• Syncopate, Thassa's Intervention: Counter someone's spell, and make a hydra. This is mainly effective since our deck will probably have more mana than any others.
• Blue Sun's Zenith, Pull from Tomorrow, Stroke of Genius: I love these cards. They're instant-speed, so we can leave all our mana up until right before our turn, then spend it all on one of these.

Sorceries

In addition to more 2-mana ramp, we also run some other great spells.

• Animist's Awakening: Best used when we can activate the Spell mastery clause, but sometimes we might need to cast it anyway if we're missing a lot of land drops.
• Exsanguinate, Torment of Hailfire: Very powerful win conditions. Even if they don't close out the game, they can give us a large Hydra, and Torment will likely erase our opponent's boards.
• Finale of Revelation: It's sorcery speed, but it's incredibly powerful if we get the necessary 12 mana to cast it with X=10.
• Open into Wonder, Overwhelming Stampede: Combat-based win conditions that rely on us having several large Hydras beforehand.
• Villainous Wealth: Just an incredibly good value if we choose the right opponent. Generally X should be at least 6, but more mana spent means more cards we get to cast.

Creatures

This deck is not very creature-heavy, since it mainly creates creatures with our commander. However, all of the creatures we do run are very useful.

• Kiora's Follower, Sakura-Tribe Elder: Some more 2-mana ramp. Kiora's Follower can't color-fix us, but it can untap Zaxara or Thran Dynamo for even more mana later on.
• Corpsejack Menace, Nyxbloom Ancient, Deepglow Skate, Kalonian Hydra: Ways to get more mana and more counters.
• Gargos, Vicious Watcher: Mainly here to help re-cast Zaxara, but it also discourages spot removal on our creatures. Note that it doesn't work on abilities, so Meteor Golem effects won't trigger it.
• Herald of Secret Streams: This card is ridiculous. Making all our tokens unblockable for as long as it's alive is crazy. In late-game, this is another win condition.
• Hydroid Krasis: Fresh out of Standard, he can do it all. He draws cards, he heals us, and he can help block flyers.
• Nimbus Swimmer: This one is just because we need flyers. Annoyingly, it's not even a Hydra.
• Selvala, Heart of the Wilds: This card is powerful in many green decks, but it's especially good here. If we make a big token, we draw a card. Then Selvala taps for even more mana, so we can make our next X-cost spell even larger.
• Steelbane Hydra: It's a lot of mana, but having repeatable artifact/enchantment removal can be very useful against some decks.
• Stonecoil Serpent: Just a nice blend of keywords. Plus its mana cost is just {X}, so we can make X at least 7 even on turn 4.
• Thunderous Snapper: While they're on the stack, the CMC of an X-cost spell is determined using the actual value of X we chose. So this will draw us a card on almost every X-cost spell we cast. Plus, it's a Hydra.
• Vigor: Obviously, just a very powerful card.
• Whiptongue Hydra: Some games, this card won't be very useful. But other games, you can wipe the board of that Ur-Dragon player, and get a 10/10 with reach.

Infinite mana

Freed from the Real and Pemmin's Aura are both 3-mana auras which have the ability "{U}: Untap enchanted creature". When they're attached to Zaxara, this allows for infinite mana of any color. I specifically didn't include these because I don't want to win the game just because of a combo with my commander and one other card, and I feel the deck is strong enough in my meta without them. That said, here's the strategy if you do run them:

• Exsanguinate and Torment of Hailfire are your win-conditions.
• Pull from Tomorrow, Stroke of Genius, Blue Sun's Zenith, Finale of Revelation, and Hydroid Krasis can draw your entire deck.
• Thassa's Intervention can tutor any two cards from your deck.
• If you don't have any of those, you can just make some infinitely large Hydras and protect them until your next turn. You might still need a way to make them unblockable or give them trample. If you have Lightning Greaves, you can try to kill one player on this turn.

TODO

• more card draw
  • idol of oblivion
  • colossal majesty
  • mind spring
  • gadwick the wizened
  • kindred discovery
• maybe take out TotFG for a non-land
• spark double for redundancy/protection
• some tutors