With all that in mind, I see a set like Champions of Kamigawa as a real triumph for Wizards of the Coast. Now you might be saying to yourself, “Hey, this guy writes for them, so they're just paying him to praise them.” Well, neither my editor nor any of Wizards of the Coast's yakuza enforcers have threatened me or offered me bribes to say such things, and I'd be just as happy saying them in some of the other places I write about Magic. Champions not only has a look and feel that is just a real aesthetic pleasure, it combines a lot of my favorite things in Magic sets: as a set, Champions is not overly dominated by any of the new mechanics like Soulshift or Arcane, and as a set it also appeals to the old fogey in me by revisiting old ideas.
One of those great old card ideas that they've revisited is the new Mana Flare, Heartbeat of Spring.
Heartbeat of Spring is one of those great cards that asks you to take big risks but can also truly offer a big reward in return. Jamie Wakefield used to joke to some of us that Green was the “color of sharing”, and Heartbeat definitely is about sharing the love. Doubling everyone's mana is a risky proposition. Usually it's going to be some other player who gets the first crack at using all of that extra mana. In group games, you might become everyone's friend (at least for a second), but things could quickly swing out of control before you get a chance to get in on the fun of all of that extra mana. In one-on-one games, you'd better have a pretty big plan on how to march back into the game after giving your opponent that much mana…
A bit of Magic psychology (for the mana rich)
Maybe it is just human nature, but something really funny happens when you give a Magic player a lot of mana: they usually empty their hands. If they are a combo deck, this can be a very scary thing, but thankfully combo deck players are meanies and you can pick up your cards and find a new opponent if they're going to be jerks like that.
So, there you are. Your opponent has just emptied their hand of every spell that they have that is not a counterspell, and now you're going to have to find some way to deal with all of these new threats. What on earth should you do?
Whether you run with Obliterate or Haups, most of the time the only card that will survive is the Heartbeat of Spring. Most people don't play as many enchantments. A little research will show just how true this is. Take the recent State Championship Tournaments in the United States, for example. 4 Phyrexian Arena, 4 Glorious Anthem, 3 March of the Machines. That's it in the main decks of winning decklists in the entire United States.
Trust me, Heartbeat is going to be one of the few cards to survive.
Truly divine
With all of the new cards out there, the first ones that come to mind are the ones that can actually survive an Obliterate or a Jokulhaups: the Myojin. The Myojin are spirits so powerful that they are almost godlike in their abilities. When you're spending between eight to ten mana on one of these spirits, getting that divinity counter and being indestructible is a great bonus. All of the Myojin can expend this divinity counter for a big effect, but two of these are pretty quickly discarded as not being all that impressive. Removing the divinity counter from a Myojin of Life's Web lets you put all of your creatures into play from your hand, but with that much mana at your fingertips, generally that isn't going to be all that amazing. Using a Myojin of Infinite Rage is also a bit disappointing, if only that you'll often want to be able to make use of all of the mana that Heartbeat of Spring provides, and turning your Myojin into a very killable 7/4 seems like an untrustworthy plan; remember your opponent is likely to have cast a few spells of their own on the previous turn.
From there we get to step up to more powerful effects in Myojin of Cleansing Fire (Wrath of God everything else) and Myojin of Night's Reach (empty all opponents' hands). Myojin of Night's Reach is especially powerful in a group game, but again, how many cards will people have left in their hand after you've doubled their mana?
The real gem is Myojin of Seeing Winds. When you remove the divinity counter, you get to draw a card for every permanent you control. The blue Myojin weighs in at a small 3/3, but that hardly matters. When you draw cards, you can generally expect to draw a minimum of seven, but oftentimes you'll draw much, much more with it. With double the mana, it won't be that big of a surprise if you simply win the game right there with all of that card draw.
You don't need to just look to the Myojin for your big creatures. Anything expensive and ridiculous will do. Darksteel Colossus survives nearly anything too. With only four mountains, a Dragon Tyrant will kill an opponent in one blow, and that is after paying the 
upkeep.
Other magical spells
So what are some other ways to take advantage of all this mana by planning ahead? One of the first things you can do to reward yourself is play a card that went very well with Mirari's Wake: Time Stretch. Taking one turn extra turn is amazing, especially with so much mana. Taking two is really, really ridiculous.
In a similar vein, a card like Uyo, Silent Prophet can be especially deadly. If you don't win the game by using Uyo to copy some spell repeatedly (very repeatedly, with that much mana), you're likely to be in a heap of trouble, but I bet that on turn 6, an Uyo copying a spell up to three times can cause a heck of a lot of trouble.
In fact, Blue seems to have a huge collection of completely mean things to do with a lot of mana. Besides Time Stretch, there is also Denying Wind. Denying Wind can be a bit of a knockout punch for a deck that you've already dealt with. Sure, it doesn't solve any problems you already have, but what it does do is take care of any problems that you might have.
Then, again in Blue, we come across the ever-wonderful “untap” mechanic. Cloud of Faeries and Snap have already found their place in Extended, but when you're talking about what you can accomplish with Heartbeat of Spring out, why think small? Think big! Palinchron and Heartbeat of Spring make infinite mana at a mere six lands. With six or seven lands cast a Palinchron and return it to your hand. Every time that you do this, you net mana. Toss in a Stroke of Genius, Fireball, Kaervek's Torch, or nearly anything, and you're likely to get a game win right there.
For the less comborific player, simply building up card drawing can be nice. Back in the day, players tried to abuse Mana Flare with Browse in a deck usually called “Turbo Book”. The basic idea is that for a mere two lands, you can find a really great spell and quickly overwhelm your opponent with your answers. At some point a recursion mechanism like Soldevi Digger could be used to recycle your spells. Nowadays, you wouldn't need a dedicated recursion element… Beacon of Destruction can do the job nicely all on its own.
Wrapping Up
All this talk of Jungle Book makes me nostalgic for the good old days when I used to play with Call of the Wild/Mana Flare. Let's revisit this fun archetype!
Creature (23)
4 Sakura-Tribe Elder 4 Budoka Gardener 4 Eternal Witness 4 Viridian Zealot 2 Duplicant 2 Shivan Dragon 3 Kumano, Master YamabushiSorcery (3)
3 ObliterateArtifact (3)
3 Sensei's Divining TopEssentially, this deck has a lot of good ways to get out mana. Between Gardener, Tribe-Elder and Heartbeat, you should be able to get to 4 mana on turn three fairly often. The Sensei's Divining Top keeps the deck flowing smoothly and will help you either complete a combo with Call of the Wild or help you find a timely Obliterate. The Shivan Dragon and the Kumano are both really fairly ridiculous once you've got a Heartbeat of Spring out, but you can always just pop them out of the deck if you prefer something like Fireball. Sure, you'll weaken the Call of the Wild, but you'll also at least have a way other than Kumano and Obliterate to get rid of creatures. Overall, I think the deck is a really fun one, and I hope you enjoy it. I don't think it is nearly as good as the original Standard Mana Flare deck I built way back in 1997, but that's only because it doesn't run Orcish Settlers.
Have a great New Year!