So... I have to admit I just hate them both, and probably Zhjaeve most out of the two. Her "knowing" is just bloody annoying to me!

Their spell system is sucky, to my mind, as the level of enemies one encounters when one is forced to have them in the party is quite high, so that any "save and avoid all damage" type of spells seem to be saved against - a lot. Or their spell selection is just ineffective.

Take Sand or Elanee - their level seven and beyond spells just kick ass or at least cause some damage, most often.

If anyone loves having Zhjaeve and/or Ammon, pray tell how you use them.

To me, they seem underpowered, just to be tolerated for sake of necessity and compensated for. Anyone else here feel the same?

The main problem with them is that the poor AI really shows through when managing their abilities. Zhjaeve can be a pretty good cleric- good for buffs and healing, with some high-level offensive spells as well (if targeted correctly), but the AI will either blow all the buffs the moment a rat comes into sight, or fire off offensive spells at the strongest enemy around (who can make its saves), while neglecting buffs that would have actually been useful in such a fight. Ammon Jerro can actually be pretty good on the offensive side of things- while his invocations don't have the damage against single opponents that an equal level melee character can have, being able to chain them between opponents can do significant damage to groups of enemies. Plus being able to choose some types of elemental damage, or status effects to add on to the invocations makes them quite versatile. The problem, though, is that most of the time the AI doesn't even use the invocations, but rather just has Ammon run up to an enemy and start whacking it. Or if it does use his abilities, it's to summon up a useless undead.

Short version, while the two can be useful, you need to micromanage them yourself to actually use their abilities properly, which can end up being a bit of a chore.

Clerics are actually a very good class; Zhjaeve just has poor stats and domain selections. She certainly can be used effectively, it's just a matter of having the right equipment and spell selection. Warlocks, on the other hand, aren't a very good class; they're not bad at low levels where other spellcaster will frequently run out of spell slots, but by the time you meet Ammon a pure sorcerer or wizard will have so many spell slots that they will never run out in any realistic scenario. Still, Ammon should be able to deal decent damage with some of his invocations and he'll be a servicable ranged-support character.

Totally agree with Phoenix; these are characters that need micromanagement. Do not leave the AI to its own devices.

Clerics can be very powerful.
With the right domains and stats, clerics can be better warriors than fighters (extended or persistant divine favor, divine power, battletide, bless, aid, prayer, . . .) or they can be almost mages but in a full plate and with twice as much HP.
But you need the right stats and domains and I must admit that Zhajive is far from perfect in that sense. But she is definitely not useless.

Warlocks can be very powerful too and Ammon does not have the worst stats. But you need to use the right spells and the AI is very poor regarding that.

I have a different problem with them. I want to know more about them but I can not increase my influence though I have them in my party most of the time. It does not go down either so it seems they are very hard to influence. Same goes for casavir but he is rarely in my party.

That was definitely a problem with them. They join so late in the game that there's a pretty limited set of opportunities to raise influence, so unless a person has looked up where the influence gains are and really games the system it's difficult to unlock all of their dialog options. Ammon Jerro is a bit easier, due to the influence "transfer" from Shandra (assuming you had good influence with her), plus a couple of other dialog options that give decent boosts in influence (but require high-level skill checks, and results in a loss of influence if failed). Ultimately, though, while Ammon has a few interesting things to say once you get to know him, Zhjaeve remains pretty boring even if you unlock all of her dialog options.

Is there a way to change the infuence on group members with a command?
I hate cheating but all I want is to hear the whole story of the game and I have finished it already.

Press the Tilde key & type
debugmode 1
hit enter & then type

rs kr_influence
& hit enter

Type
debugmode 0
& hit enter

Hit the tilde key.

Thank you all for comments - at least it puts my mind at ease that probably these characters just are hard work to get the best out of them.

AI is not NWN forte for sure.

Zhjaeve not being blessed with great strength, dexterity, constitution or melee excellence despite her divine calling, why does she want to rush to the thick of the combat I always wonder!?! And same wonder goes through my mind whenever Elanee shape-changes into form that cannot handle the weight in her inventory... :-p

I also tend to find Zhjaeve rather sanctimonious, so she annoys me a bit with her "know this" and "know that"... Ammon being evil is more fun for personality, and somehow touching through his tragedies, but maybe once I should push myself to play warlock to get an idea how to get something out of this class... To think this was the man who shattered the sword in the opening animation!

Well, I will try to see that maybe this is not too bad, in order to give additional challenge to the latter part of the game when the party generally starts being pretty powerful.