Hand of Necropolis was unlocked at the castle after the 2nd demon battle (see screenshot), though I was only able to buy it after finishing the 3rd demon battle. It should be noted that most of the suppressable items are in the 1st island. The reason why I was able to buy 3 AKs, Hand of Necropolis, all suppressable items, and stock up on guard and repair droids is because I started suppressing the weaker items while I was on the 1st island; more battles mean more gold as battle rewards and via dragon dig.

Btw, I tried replaying against humans in the 2nd island, but stop playing after the 1st human battle. This is because the human battles generate the weakest enemies, at least it does for my game. I got 5.8k from that battle wherein the parallel dwarf battle got me 8.5k (both with HoN and AK on); that's a 2.7k XP difference. I know this would be the trend for the other 2 hero battles since I could see them as just "lethal" as well, wherein I see the dwarf battles as "invincible". Given an estimated trend of losing an average of 2.7k XP per battle for 3 battles, that's 8.1k XP difference. And given my "luck" with level 4 suppression battles I might just end up getting 7.5k from the Inquisitor's Blade, a net loss of 600 XP. Even if the conditions had some variations/fluctuations I estimate I still need a net gain of 10k XP to get to level 30.

I still might give it a shot; you'd never know for sure if you don't try, right? :) But I've already done 2 complete runs of DotC; time for some OotM first. :)

I not so good on english so I dont understand what this means ====>>>>
Increases 1 after each battle, +2 if enemy undeads
Decreases +4 humans/elves, +3 Inquisitors/Paladins

Its best use that sword when meet paladins?

I have try load a older save now but when I digging for a scroll so thats come always same item when I try digging again after I start the fight again :(

I buy that hand on second Island... Why you dont get more points when you have use more AK than me??? The answer is.... I dont know :(

Yes, it is best to use the Inquisitor's Blade when you go against human and elf enemies, especially if they have paladin and inquisitors with them.

As for using the dragon to dig chests you need to change how you fight the battle. For a simple example, let us say your army is composed of only one stack of repair droids placed in the middle slot. If on the first turn you don't move and just attack then you dragon dig at the start of the second turn, this should give you a different result if on the first round you move your repair droids 4 spaces forward then attack then dragon dig at the start of the second turn; the fact that you did something different should randomize both the location of the chest and its contents.

The answer is you had harder and more powerful suppression battles, thus the base XP from those battles were far greater. Take for example the baton of leadership; it takes 3 suppression battles to fully upgrade it, and that last suppression battle is one of the hardest suppression battles for all items.

There is also a large randomization factor in suppression battles. For example in my CotA game my Mask of Hate suppression got me 25k, while in my DotC game I only got 14.5k; the amount of enemy units generated in my DotC game was simply a lot lower than in my CotA game (see screenshots below wherein my CotA game Mask of Hate suppression generated 6 more Archdemons).

Thanks for the answer :)
I shall try find a AK scroll and fight all battles with Inquisitor's Blade,, I think I come to level 30 :D
Yeasterday I upgrade Mask of Hate and see that give me around 2000 points in OotM without AK. (thats on hard and not impossibel)

Definitely harder to finish Imp no loss than CotA. I managed it today after a lot of false starts, going paladin (never used paladin before), doing the first battle with RD and AD, the second, third, fourth and fifth with a combination of RD, AD and giants (sometimes ONLY giants, easier to keep alive) and the final battle with 2 black dragons after dumping the other units.

Quite abysmal score, I guess, only 694.

Mage run
 

Impossible, no-loss run as a Mage, reaching level 29.
It was my second run, (the first was only lvl 27), which differs from the first only in the second island. The first island was a human against orcs. The first battle with 2 paladins in one stack, the second with a single troll, the third with 2 trolls in one stack.
The second island was against Necromantas, with lizard artifacts. Both of them were giving better score, because Necros gave about 2000 more XP than humans (dwarfs were the weakest), and lizard artifacts gave two Rings of Youth, (elf artifacts didn’t give any upgradeable). On the first island there were Dress of Magessa (8414), Adept’s Staff (3033), Archmage’s Staff (16072), Colonel’s Baton (4666), General’s Baton (6986), Marshal’s Baton (12216). On the second island, in the chest: Snake Ring. It’s interesting, that this ring from the chest was the only artifact, which gave different XP in the different runs (8884 or 10412). It means, that the defenders were generated only when the chest is opened, not when the game started. It’s interesting as well, that the gremlins are differs time to time in any upgrade battles, not the number of them, but the type (evil or friendly). With the two Ring of Youth (7190 + 6422) in the second run lvl 29 was reached, but still pretty far (cca 10000) from lvl 30.
The second island was done by BDs and GDs, in the first run without-, in the second with Ress, which was much much easier keeping a few Inquisitors in my army for bringing back GDs.
I’ve had 3 AK scrolls on the first island, and used them for all of the upgrades and for the 3 battles on the second island (12 battles together).
Reaching lvl 30 seems possible, although it needs one more highlevel upgradeable artifact, or the suppression of Inquisitors blade, or a Hand of Necropolis with some luck which gives stronger enemies.
Scores, Heroscreen and Spells attached.

it's such a pain to get a good initial save that is worth saving and loading for an AK scroll.

:(

Just an update, unsure if OP is still around, it's 14 years later!

i managed to hit level 30.

https://i.imgur.com/fbwc937.jpeg