Ok, so as someone that really enjoys Vodyani, there is one thing that is nagging me. Currently all factions can assimilate minor factions into their forces. When they do this through either diplomacy or conquest, the system falls under your control. Understandably the Vodyani do not have this benefit. Currently, beyond denying other players the bonus of eating other factions, the Vodyani are more or less hurting themselves with this action. Minor factions, particularly on the larger maps, as i may or may not be pushing myself past the medium setting, tend to be the primary way to get essence. Might i suggest that we change the UI as tad, and add a bonus to eating other factions. As such, instead of naming it "Raze system", change it to "Harvest system". The current mechanic would remain the same, however the Vodyani player would get 100 essence per population from the minor faction. This way i would be able to gain the needed essence to get more arks in a competitive way.

Or as a different idea, make it so when a Vodyani brainwashes a minor, this generates a trickle of essence based on their population size. Make it so once brainwashed they operate as Ai, where they will gain the player colours, and send out patroling fleets that are friendly to the player. They provide the bonus of the minor faction, and at any point, can then be further harvested for a lump sum removing them from the game. 

You might want to post this in the "ideas" topic.

The voydani will get a "hunting ground" feature that will transform any system they have conquered into a hunting ground (basically it's a raze ability specific to the voydanis that remove 1 pop/building per turn). The voydanis are then rewarded with essence by these hunting grounds (they can get much more essence if they anchor an ark on the hunting ground though).

it should work for both minor factions and major factions too

I noticed this as well, I assimilated a couple of minor factions and got nothing, wasn't sure if it was a bug or design flaw, but I too felt like I should have gotten some essence per turn.

So that is my story (and probably yours). 

I created my first Vodyani game, and Hisho were just above my home system. Then, i took the quest to assimilate them and..... they simply disapair! And my leecher became useless on this system.

And now i see that Vodyani start their game with the most unuseful technologie of their race:  Xenobiology!

What the point to be able to discuss with people you only see as food? And what the point to have farm when your food are actualy people of others races and you have only 3 pop slot on your home system?