Instead of thinking too much, it would be better to just try it directly.
Su Yuan immediately issued an order, saying, "System, consume 5000 Star Dust to upgrade knowledge!"
"Unable to upgrade."
The system's voice rang out, and the panel didn't change at all.
"Can't upgrade directly..."
Su Yuan looked thoughtful and continued, "System, upgrade 5000 experience points."
With the surge of system energy, the experience bar increased by 5000, reaching 5000/5000 directly.
"Fortunately, I can upgrade experience!"
Su Yuan thought carefully for a while and roughly understood the reason behind it.
The Star Dust System, although it could create something from nothing, also needed some basis.
Skills could be directly upgraded continuously because all the information about the skills was stored in the Star Card.
