what does advent deliverance engine do???

It costs a lot of credits.

it just say amplify your culture on other planets or anything... i can't seem to understand it's function....

you can overwhelm enemy planets with culture, but you need an insane Number to do serious Damage..

Increse your culture on the planet fired at...which can improve your ships that is in the area's shield migitation by 6%, with proper research...tactical weapon...but if the enemy wasn't aware you might to cause rebellion on the planet...(if long enough...)

Vasari Kostura cannon disable all the orbital structure and ships for a limited period of time, and cause some damage too...tactical weapon...

So both of them I think should be used as a lead for attack...

The Engine is meant mainly as a massive support weapon, not a direct planet killer. It can flip planets if you chain enough shots since it has a massive culture spread and lasts a while, and it's easiest to do with the empire's border planets that are below 50% allegiance.

The main shining point of it is that basically you can get your culture bonus (+6% mitigation) anywhere on the map and at the same time deny your enemy his. For example, if you're attacking a Vasari player on his home turf, you can deny him his +15% damage bonus from culture and at the same time directly increase your own fleet's damage reduction. 6% mitigation might not seem like much, but it translates to a considerable damage reduction:

Say you have a ship at 60% and you get shot for 100, you'll take 40. Now with the Engine, you have 66%, so you'll take 34 points, that's 6 less damage or (6/40) = 15% damage reduction, and adding that the enemy fleet does 15% less damage (if Vasari), you get a combined 30% reduction in damage taken. Now Advent's shields typically cap out above 60%, so the actual damage reduction from the Engine will be higher in most cases (going from 70% to 76% mitigation is a 20% damage reduction).

The Kotsura disables all orbital buildings for 3 minutes, all enemy ships for I think 15 or so seconds, and does 10% of their max (not current) hp in damage. It's a great weapon for breaking through those 35 point defensive turtles

cool...   

What's the range on these cannons? I've seen various answers and have never bothered experimenting myself. At first I thought it was through phase lanes but I remember I shot a cannon further than that before.

ffs pearoast

They can be shot anywhere on the map, even at planets around other stars. Doing inter-stellar shots however takes an insanely long time since they don't fly nearly as fast as ships in phase space.

The Deliverance Engine works by effectively giving you a culture rate on the planet you fire it at. If you look at the info card for a planet where you have a Temple of Communion (or any other culture building), you'll see "Culture Rate: 4.0" or something like that. Thats the rate your culture is growing at the planet, and it spreads out from there.

When fired, the Deliverance Engine will make the enemy planet act like it has your cultural buildings for a while. The rate is actually pretty high, I think around 12. Firing two of them at one planet can completely swamp enemy culture in everything nearby as long as the effect lasts.

Its useful both for getting your own culture in an area (for the mitigation bonus), and to stop enemy culture so you can colonize the planet more quickly. I rate it as the #2 special weapon personally. Its no Novalith Cannon, but I find it more useful then the Kostura Cannon.

The Advent also have a research option that gives you an up-to-date view of sectors under the influence of your culture so on top of the other bonuses, the Deliverance Engine can give you a good look at the opponent's empire.

Plus, even if you don't completely knock out planets with it, reducing allegiance across your opponent's empire with culture will still cut into their income pretty badly.

i've been hearing about this rebellion thingy... i fired 10 shot on an enemy planet but i can't get it to rebel... lol

When a planet's allegiance hits 0% (which, for a 100% allegiance planet, would take ~28 minutes of heavy culture-barraging), the opponent loses that planet.

Allegiance loss per-second is capped at .07 right now so hammering a planet with more than one DE shot isn't likely to make things go any faster.

i built five on my custom planet and i'm firing at a 25% allegiance... does broadcast center affects this or cancel your barrage?

Deliverance engine also increases the damage of friendly ships in the gravwell of affected planet by like 15% or something.