[Radek]

1. The Toughen bug. When you enter a town, all spells are removed from your characters. Now, if you cast Toughen, you get 10 HP temporary. If you enter a town while the spell is active, the spell is cancelled but the temporary HPs are not removed. They become PERMANENT.
The Toughen spells stack. You can cast 4 Toughens on a character and enter a town. Your character gains 40 HPs permanently.
The advantage (or rather a piece of cheese [img]smile.gif[/img] ) is still only temporary because of the method of computing gained HPs during levelling up. Good, you have gained 40 HPs by means of the Toughen bug now. When you will level up, the game will see that you have too much HPs and give you only 1 HP. This will repeat as long as the game will see that you have too much HPs. You will lose the advantage gradually.

2. Revert Adventure cannot help you in training. The Rever Adventure button is available only in the inns. It loads an emergency saved game and returns your game to the point when you have left the town for the last time.
Additional training is possible by another option - Reset Adventures. The option is available in the town exterior and returns the game to its very beginning - without reseting your characters. Your characters will keep their levels, items and abilities. They will lose certain quest items and membership in guilds, that's all.
The Reset Adventures action has one additional effect - it clears your role history. As we know, you cannot return to a previously taken role. If you are a paladin -> barbarian then you cannot become a paladin again. But the Reset Adventures causes that your paladin -> barbarian becomes a pure barbarian, which can become a paladin again.
Therefore, you can do the following: Play the game for a while, change roles, and reset adventures. The game is at its beginning and your role history is purged. You can continue training (all monsters are back so that you can gain XPs, all quests are available again) and changing roles as you need. Then you can reset adventures again and take next portion of monsters with a new role. It can be a bit boring but it allows you to train as long as you want.