River Surges in Sunlight/Build Diagrams

=Massive Flooding Loop=

The goal of this build is to trigger the max tier of Massive Flooding from turn 4 onwards - this can be achieved because River's Bounty + 1 energy per turn + 1 energy on reclaim is just enough to pay for River's starting hand. The first key step is to reclaim River's Bounty on turn 2 so you can afford to play a 1 cost minor if necessary on turn 3. You can only spend 1 energy on turn 3 and can only play 1 unique, otherwise, you will not be able to hit Massive Flooding on Turn 5 (You could play something other than Boon of Vigor, as long as you don't go over your energy budget). From Turn 5 onwards, you can reclaim loop your starting hand and any zero cost minor. When pushing invaders, move them towards the coast to make Flash Floods more effective (It can destroy 2 coastal cities when paired with Massive Flooding, but only 1 inland city).

Note that River does not need to take Boon of Vigor on itself to make this build work, and should give it out as much as possible. In solo, Vigor allows it to stockpile energy and afford late game majors.