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It all depends on the player's skill level. The genocide on Hypatia is usually carried out by more experienced players who quickly acquire the funds to gather spells and experience to level up their elemental skills. They collect Fire Wall, which compensates for the lack of backstab damage and also turns places like the Dead City into a safe zone. They also use Lightning and Fireworks, the latter being practically the main skill for a backstab-focused character. As a result, after Hypatia, the character has Backstab 52, Elements 68, Senses 80 (thanks to Airi), and Astral, around 35. Perks are not leveled up at all. After Ingus, Endurance and Restoration (doubling mana and mana regeneration) are increased, and Backstab is brought to approximately 80. On Suslanger, Elements are maxed out (99, since the 100th skill is not needed), Astral is around 80, and Acids are at level 3. This is precisely why Backstab should not be leveled up, otherwise, there won't be enough points to max out Acids. Backstab can be ignored at this point; Imperials will constantly hit anyway, and you won't even notice the others. The result is a pure mage, wearing meteorite armor and wielding a dragon sword. He can't run, but he doesn't need to. The main thing is not to forget to collect 4 meteorite batteries (a staff with a rune for permanent effect), providing 100 healing for 20 mana. After that, the character starts casting the spell My Immortal.
If you want a simpler playthrough, level up Backstab to the max (remember that any perk should be leveled up to 3 immediately, as this is more efficient in terms of experience cost) and also Backstab. Then, proceed as described above. Acids won't be maxed out, but that's not necessary, as the character has a huge amount of health.
By the way, steel batteries should be collected on Ingus as soon as possible; after that, the problems will disappear.
Good luck with the playthrough of the best single-player game among all Russian RPGs.