'These training chambers are just marvelous, as the possibilities of potential for growth and learning seemed endless,' Alex thought, as his mind went through all the info he had just learned.
The lone ability to enter an illusion that is as good as reality was no different than virtual reality, and being able to pick a perfect opponent from a massive database with the ability to repeat the cycle without the worry of death.
The other stages were also just amazing, to say the least, as experiencing the memories and experiences of someone else, like an elemental Ruler or someone who had mastery over various battle arts and so on, is just something of extreme value.
The ability to experience various events throughout history was just another big one, as it granted the experience of something that otherwise was not possible.