P.S. Level 8 (9000 xp), level 9 (11000 xp) respectively, 2000 xp.
P.S.S. And have you tested this on a single-player battle, with neutral creatures (or a computer-controlled hero), where a hero controlled by a player levels up during the battle? In other words, can we say that the experience gained by the player-controlled hero during the battle does not affect the probability of a level-up?
2) Most likely, if the battle is over and our hero gains at least one level, then - yes.
But how? Did you arrive at these conclusions analytically and confirm them through practical testing?
If this is the case, then it's really unfair... the computer is cheating again! Why did the developers do this, implementing an illogical algorithm? i.e., the computer should level up, killing our monsters, so that the probability of a level-up is higher!