Esus if converted to also offers unrivaled! diplomatic power (no diplomatic penalty for running a different religion which nets to a whopping 6 points of difference in relations given time. Which usually equals the difference between "slightly annoyed" and "slightly pleased".
Its also possible to combine that with both! of the councils which overall nets a further enhancement of relations based on the situation most favorable in an actual given game.
Add Trust (Spirit 3 Spell) to that mix for all Civs that start with Spirit-Mana (thanks Kael Coalbane
) and you should be firmly set in friendly territory with all your neigbors.
Which means most Civs won't attack you anymore (unless they did already prepare for a war on you before! going friendly.) no matter how weak or exposed you are... . Just be sure to know those few civs / leaders who still do (Doviello for sure, Infernals most likely, Hippus as well i believe and some others). So you don't get backstabbed / pounded into the dirt unexpectedly.).
Which makes it the! best religion in some setups (map, civ, situation in game...) and for some (mostly non-agressive) play-styles (and those will deliver wins up to deity. And should still do so even in the harder environment which the mod has become in the most recent versions. Strategies which rather reliably win deity games are not all bad or inferior in my book. And those are exclusive to Civs actually running Esus.)
So there are 2 enormous benefits exclusive to a civ running! esus (as opposed to having it as a secondary one. Which doesn't work well with most other religions (since most of them rely on priests and/ or religious heroes which is not even so true for Gibbon / Mr. Coalbane and Esus which can turn into a Lich or flesh-golem rather easily in comparison if you really must switch and have a contender which also aspires to hire him to his cause) and is also brilliant.) if you play it right and it fits your playstyle (if both is not for you then its no wonder you! dislike it. Doesn't mean its bad or useless overall.).
Just because its not blatantly obvious (that includes both diplomacy and the attacking out of the blue without giving the AI an option for Defense.) or all powerful in pure military terms doesn't mean it doesn't exist...
First ask then state, lest half the forums get it wrong from taking your word as truth (As seen here and elsewhere. Where comments are repeated and copied without closer examination or confirmation.).
Also its a broken/defunct mechanics in some regards vs. human players since you shouldn't be able to discern a player running Esus religion either by units or by any source of information.
That's not implemented yet but according to some comments from the team its supposed to work that way or at least has been planned that way at some point (don't know the current standing on that one.).
Just that at other features the intended feature is the basis for evaluation usually, not the defunct one. Not so much here which seems a bit odd to me...
A neat way imo to actually achieve that result would be to always display the religion a player is running as the religion the esus-player runs (So if for example you run order he is shown to run order with all things including alignment indicating so. With concealment in the diplomatic relations and on the bargaining table as well, so that there is no real way around it even by looking at inter-civ relations...
That should be doable without extreme hassle.
Either by not displaying the relations of human players to the AI and vice versa to other human players at all. Or by disguising it if that is possible codewise.) and a unit with HN (Promotion) should have a nondescript unified look to other players (black robed and hooded figure or something simmilar if SeZereth really wants to take the time to do so, or someone else from the community cares to nicely do so.
) which also hides the promotions in mouseover and just displays raw strength or at least all promotions which make identification of any sort possible. (that system of promotions deciding looks is already firmly in place so it shouldn't be hard to code in at all.)
It works like a charm vs. the AI (which was the focus of the team at setting the system up most likely) and the multiplayer part can be done given time i believe... (above-mentioned procedures would be one possible way but I'm sure Kael + Team will come up with what works best for them...)
Diplomacy is not imposed on human players for obvious reasons so that advantage is rather void in competitive multiplayer of course.
But that's not really sensibly fixable imo (without making the game worse in my book). Not a real fault of design though given that FFH2 is geared more towards singleplayer and cooperative multiplayer and a game can hardly be anything... (far from all features are as good if used vs. other players in comparison to a game vs. AI or if allied with all other players and vice versa.)
Still that said a late-game (Shadow?) Hero for Esus might! be nice (and i would surely appreciate my favorite religion getting a beef-up.). For the the empyrean an early game one at the founding tech surely as well...
I'm just not sure its utterly necessary (and in my book fixing the display of units and religions to really disguise you running CoE is far more important in my book...).
But i have to say i would really! like buying healing pots for 10 or 20 each (normal speed equivalent of course. I would occasionally use such a feature even at a price of 50 GP normal speed equivalent.) when running CoE (or as a secondary as well even though that might prove far to powerful given that its a full heal better than even an high-priest ones.) to account for missing priests... Neat idea.
Oh and one small note on another benefit of running CoE all to fast forgotten and perhaps considered irrelevant but still neat imo:
You got to play the avatar of the mods design lead in Erebus.
(Disguised as it fits the religion but still.
You can still violently turn him into a Golem or have him immortalize himself to a Lich in a horrible ritual if you crave another Religion even more. But who wants to do such a thing?)