Baldur's Gate : The Sword Coast Chronicles : NWN2 Persistent World

I have noticed a sudden increase of all the summons of the Hellfire's Warlock Summon Baatezu ability. It occurred when my char hit level 20, when the summons went from 14HD to 20HD. So, I wonder how this progression exactly works:
1) Will the summons increase further beyond 20HD?
2) Do this increase with Warlock/HW levels, caster level, character level...?
3) According to the last update log, a pair of changes have been introduced to the HW class. What has been exactly changed?

Endelyon wrote:06/02/2017
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Hellfire warlock summons rehaul, thanks to BMD.
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Hellfire warlock restricted to evil only.
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The summons change when you have more than 16 HD, there is no scaling. The changes are what is written, no more no less

Regarding the summons themselves since you have an hellfire warlock you'll be able to see the updated summons so ...

there is only the one version of the summons, they added a script to nerf them tho if you are under a certain level

Thanks for the answers Vale and BD!

But I would say that I am sure they were upgraded when my char leveled up from 13W / 3HW / 3WoD to 14W / 3HW / 3WoD. So at level 19 he already had 16 warlock HD.

Anyway, the upgrade of them is brutal. Maybe in the pit fiend is not so noticeable (although it is so), as this summon is very strong stil on its "weaker" version, but on the rest of them their survaibility and fighting capacities are increased a lot, which makes them extremely useful.

I am still waiting for the chicken to appear though. I am eager to see that damn beast in action

thats bc the pit fiend and the chicken (who is also a pit fiend) got the smallest change, just 2HD to make them 20 like the others

the rest of the summons some were only like lvl 12 and then of course the one everyone complained about, neeshka, can finally make use of her sneaks now that she has feint

so yea, good that it worked out, people shouldnt have issues with one being really weak and useless anymore