EternalObserver Allows you to max Donovan Work during Succession Crisis, maximizing damage to Donovan Score.
I should've been more clear about my question. I meant advantages aside from everything to do with Donovan.
EternalObserver Provides a massive boost to assorted Country Scores, particularly helpful for getting Givini Score up faster for maxing out Givini Orc Merchant maybe a cycle or two earlier.
Provides huge +3 Social, which makes the very tight 40 point threshold during the Succession Crisis much easier.
Boost to stats (relevant for threshholds, at least) can be as easily obtained by spending this million ProN on other investments with the additional bonus of more income. With Monument you can max Orc Merchant perhaps one or two iterations earlier, but overall you will have less money on that route. For example, +3 social can be obtained by investing in Mercenary Office + Booze Shack with additional bonus in 65 (15+50) income, which is more than +50k of Orc Merchant's income for additional 10 point in New Givini score.
EternalObserver I'm pretty interested in this "Prefect Gawnfall with Keranii" route.
For this you need majority of investments (you can skip Givini Tunnels and Helvanna Band Tour) and top threshhold stats in everything relevant (country scores, Simon hidden stats, RPs) as well as completed Sex-Purity Research and Orc Diversification.
And you must have Jhenno's support. Without Jhenno the only way you can hope to get best result in Unification vote is by breaking Esmera's deal. With Kerannii' deal or double deal top Unification vote is impossible. And breaking Esmera's deal can bite you down the line.
Also, if you allied with Kerannii, then you need to choose light reforms.
Anyway here is my take on Kerannii's deal with optimized playthrough without Tunnels:
Starting Point
Hester Acceptance
Jhenno Unification vote
Excommunication vote
Sarai (All in) No
Simon Silent
Let Carina talk Yes
Result +12 (best) (+12)
Capitalize Olive branch
Unification vote
Sarai Targert Nabith
Simon Leadership
Result -5 (best) (-5)
Succubi vote (No Andra)
Sarai (All in) Yes
Simon Nabith
Iris ask to talk Yes
Result +24 (best) (+24) Vhala +2
Ivalan Succubi
Yelarel Light reforms
Simon Silent
Sarai Join
Ask Hester No
Ask Nabith Yes
Ask Bertricia Yes
Ask Kerannii Yes
Result Pass (4 vs 3)
Succubi join vote
Sarai (All in) No
Simon Annah
Riala ask to talk Yes
Result +23 (best) (+22)
Unpeople vote (Yelarel light approach)
Robin talk No
Sarai (All in) No
Simon Silent
Result -7 (best) (-6)
Tak’kan vote
Sarai (All in) No
Simon Annah
Result +14 (best) (+12)
Purity vote (Andra talk, Qum show)
Sarai Kaskia proposal
Simon Silent
Herin Change standart
Result Kaskia proposal
Fucklord vote
Sarai Esmera (can choose almost anyone at this point)
Herin Think for Yourself
Result +16 (best) (+15)
Promotion vote
Result Overwhelming for Herin (6 vs 1)
Influence left: 18 (just enough for every minor issue).
Final scores:
Hester 4
Nabith 8
Annah 10
Bertricia 6
Esmera 10
Kerannii 11
Yelarel 15
Herin 8
Kaskia 6
Insulinde If I can do it without sacrificing too much, I would like 9 auxiliary diversity in time for the Erosian war. This effectively gets me +6 to various country scores (+1 Rodak/Ghenalon/Erosia, and +3 Zirantia because I can afford to reinforce it rather than one of the fronts). In fairness, it's unlikely this will be necessary to pass any future checks, or translate into any significant ProN advantage, so it's probably not that meaningful for pure optimisation – but I see them as a proxy for a better world (less chaos and death, more prosperity). Since I invest only 50k in the Order of Silence, to do this I need mercenary offices and either the mage guild or monument by investment phase four.
I reached 9 auxiliary diversity by investing in Mercenary Office post Arclentian war and in Mage Guild in pre-Gawnfall phase. That way I maxed Orc Merchant after opening Ruins and get more returns overall. My returns in chapter 4 (not considering 2.5k in Tower Depths, 250k from Gawnfall mercantile issue and any leftover money): meet Megail - 2555k, after Ardan crisis - 3502k, after Depths - 4127k, after Gawnfall - 4382k, after Erosian War - 4432k.
Fulminato i never see the appeal of kerannii deal. the bonus outside the synod are very little compare esmera. the only real things come in my mind is more ivala rp through ivalan acceptance for shuffling something in crystal run during IK aftermath.
On the contrary, outside the Synod it's Esmera who hasn't much to offer. Unless you consider 150k discount for Helvanna Ivalan temples and an option to choose +5 Aram for -2 Ivalan acceptance as a big deal. That's about all. On the other hand post-Synod Kerannii gives you +1 Religion and +1 Aram for Unpeople and additionally +1 Ivalan and +3 Arclent Acc in Eustrin without any cost. So statistically post-synod Kerannii is better. It's at the Synod itself where Esmera is somewhat better since you can potentially skip Lustlord Temples and still ace everything (although you will be left with lower Anna's synod score that way, which may become a problem in chapter 5). Also, you can get additional +1 Vhala RP with Esmara's deal.
P.S. Can someone clarify, if you break your deal with Esmera (on alternate unity vote) or make a double deal with Aramite priestesses, will the game consider it as a "deals off" for the Eustrin Final? Also, if you attempted a double deal, which caused Kerannii to "freeze", will that be mentioned by the priestesses at Eustrin negotiations in some way or not?