The surging Spirit Power clearly didn't break his limitations, as he could regenerate only up to how much he could, but it was like he had an extra battery, or source of Spirit Power.
As long as the beautiful owner had spirit power inside itself, then Eric would have no problem of recharging his Spirit Power to fight.
His Soul Separation had wrestled much of the connection with his conscience sea during this time and could use it in his favor and to regenerate, but the rate of that regeneration was low.
Furthermore, he didn't have full authority of the conscience sea he was standing upon, so he wasn't able to make full use of that connection, and strength.
Not to mention that in the end of the day, the Soul Separation was just a byproduct of Eric's will, and not the true owner of this place, so he still was influenced by Eric's will and thoughts.
