Walkthroughs for custom maps.

I suggest you check out the walkthroughs for Metataks, Xiedu, and 6424 Heroes.

For Xiedu, the walkthrough took 79 days (!). If anyone wants a serious challenge for the next six months, they can try to beat that time.

For 6424 Heroes, there's also a slightly different version of the map (I noticed that the gate color in the swamp area is blue, not black, so it's a slightly easier version). The walkthrough took 8 months, and they even bought out the 6424-level heroes. And there are a bunch of other 6424 Heroes walkthroughs that stalled in the second or third week :D

Yeah, completing Xiedu in such a short period is insane.
And the 6424 walkthrough, in principle, follows the same pattern until about the middle of the map. Then the chaos begins when they start releasing all the 6424-level heroes, like "let's take a mage against a warrior, let's take a warrior against a mage." It's worth mentioning the battle where the redeemed Tazik fought 99 vampires against legions of archers for the black shards. The author of the walkthrough wrote: "I set it to autobattle, and after 4 hours, I came back" :)
In general, they have their own ideas about honor and dignity when completing maps. Although the map creator said that he doesn't see anything wrong with buying out 6424-level heroes, saying that by killing them, you can feel their power and play with them.

What was confusing during the 6424 walkthrough was that the map is slightly different (the blue gates instead of black ones in the swamp area), and there are no roads in the underground (which slows things down), and a couple of other differences.
Most of the battles in the middle of the map's completion time are based on this strategy: we attack a Castle where the enemy has superior forces. We bring bears, archdevils, archangels, imps (for mana), ghosts (for mana draining), pegasi (to increase mana cost), and mages (to decrease mana cost). When attacking the Castle, we kill our own ballista, and since we don't have archers, the computer doesn't attack us. We position the bears near the walls and throw a clone into the computer's Castle, where the bear clone first takes out the flying units and then the rest. At the same time, we drain the computer's mana to 0. Then we resurrect and win. This strategy was developed and used by Richard Chen in the Wayfarer walkthrough. And it seems to have become very popular among the Chinese.
There were also a couple of things that were unclear:
1) On the 2nd day of the game, after freeing Cuthbert, why did he leave Mullich without units to expand!? That is, Mullich was without units for expansion, while Cuthbert had a horse and a knight. Is this even legal?
2) On the first week, he was defeating archangels with only fairies and no angel using Luna. Is this also legal?
3) It turns out that you can break through the legion of bears near the 3rd angel Castle without a war machine! By blinding the bears, hitting with archangels, and blinding them again.
Interestingly, angels are built in the first Castle on day 116. And some individuals even manage to capture the second Castle on day 117 (!). Although it doesn't really make much sense.