One percent of infinity was still infinity.
As for why Aiden assumed his own strength was infinite, it was due to the nature of the system. In its own words, Aiden was the strongest while inside the sanctuary barrier.
In other words, as long as someone stronger than him existed inside the barrier, his strength would automatically increase to surpass them.
So, did it mean Karina was as strong as Aiden?
It's more complex than a simple yes or no.
Logically speaking, they were stuck in an endless loop.
The moment Karina inherited partner status, her strength jumped. When that happened, the system increased Aiden's strength so he'd continue being the strongest. The partner status then transferred more strength to Karina, and the loop continued.
When that happened faster than the system's clock speed, it would crash.
At least that's what should have happened.
