River Surges in Sunlight/Antistone's Opening

I'm going to give a lengthier "opening" here, because it seems to line up especially nicely, but the later turns may get a bit vague.

-1- Growth: Place 2 presence (from bottom track) Cards: Wash Away (push up to 3 towns/explorers) River's Bounty (gather 2 Dahan, add 1 Dahan, +1 energy)

You'll want lots of sacred sites for targeting your innate. The best way to get them is generally to focus on expanding to wetlands, where your special rule (River's Domain) gives you a sacred site with only 1 presence.

The ideal use of Wash Away is probably on a land where the invaders just explored (during the same turn) but which started with a town; that land is going to build a city next turn if you don't stop it, and will resist many of the common early-game tricks for interrupting an invader action chain, but Wash Away can still defuse it in one power.

If no such target is available, Wash Away is more similar to (the first tier of) your innate, Massive Flooding. It can be used to push the town out of a land that's about to ravage (leaving 1 explorer who won't do enough damage to blight and hopefully will be killed by Dahan), or to push an explorer who's about to build (preventing the town from being built in the first place). Stopping the build is more efficient, but requires that you act one turn earlier.

Generally speaking, push stuff towards the coast to try and create inland areas that will be out of range of explore actions. Grouping stuff together is often a good idea, in preparation for the highest tier of Massive Flooding.

River's Bounty ideally targets a land where another spirit is going to be defending soon. It's range 0, so keep that in mind when placing presence. Even if you don't need the Dahan yet, for this opening it's important to play this power first turn for the +1 energy.

-2- Growth: Place 2 presence (from bottom track) reclaim 1: River's Bounty Cards: Flash Floods (1 damage, +1 if coastal) Boon of Vigor (ally gains energy) River's Bounty (again)

The 2 presence this turn uncovers 3 card plays, and also the "reclaim 1" space, which gives you a third card to play. 3 cards gives you enough elements to trigger the second level of your innate.

Flash Floods is fast, and can destroy a coastal town or an explorer who's about to build, whichever is more useful under the circumstances.

Massive Flooding tier 2 is used a lot like Wash Away, except you get to destroy one of the towns.

-3- Growth: Reclaim, gain a power (minor), +1 energy Cards: varies, but for example: River's Bounty, Flash Floods, Wash Away

In choosing your minor power, focus on elements (water and sun are both important; stone will eventually be a helpful tertiary).

You almost certainly want to trigger Massive Flooding tier 2 again. (This might prevent you from triggering it next turn, depending on your minor power draws, but since you're going to be drawing another card next turn, you probably want to go with the bird in the hand rather than saving elements that might not matter next turn.)

-4- Growth: Place 1 presence (bottom track), gain a power (minor) Cards: all available (careful what you reclaim--see turn 5)

You now have 6 power cards total (4 starting, +1 on turn 3, +1 on turn 4). You played 3 of them last turn, leaving 3, but you get to reclaim one, giving you 4 to play this turn.

If you got highly favorable draws, you could theoretically activate the highest tier of your innate this turn.

-5- Growth: Reclaim, gain a power (minor), +1 energy

You can now definitely activate the highest tier of your innate (no matter what minors you drew) by playing all 4 of your starting cards.

In addition to being generically awesome, Massive Flooding tier 3 combos nicely with your other powers (Wash Away can group things together to be destroyed all at once; Flash Floods can weaken cities so Massive Flooding can destroy them.)

Make sure you have enough energy for this turn. If the minor powers you gained on turns 3 and 4 both cost energy, you should make sure to play River's Bounty on both turn 3 and turn 4 (using the reclaim 1) in order to have enough energy to play all your starting cards turn 5. If one or both of the minors costs 0 energy, you have some more flexibility. (You can also get extra energy by targeting Boon of Vigor on yourself, but it generates more energy for an ally.)

Variants: You can swap the order of Wash Away and Boon of Vigor on turns 1+2 if an ally needs the energy right away. (But you need River's Bounty turn 1 in order to afford Flash Floods on turn 2.)

If you take 1 presence from your top track on turn 1, you get an extra energy every turn, but don't get to reclaim a card on turn 2, so you end up with 2 additional energy on turn 3 (+1 per turn for 3 turns, -1 you don't get for the second River's Bounty). That means you'll have 5 energy on turn 3, which is enough to plausibly get a major power on turn 3 or 4; if it's cheap, you can use your reclaim 1 spot to play it over and over and over.

But the way I see it, the main advantage of major powers is dealing with built-up lands that simply have too many invaders to efficiently handle with minor powers. River is able to handle those problem lands using the highest level of Massive Flooding, so I think it's generally better to just get a ton of minor powers and card plays to help trigger it.