The sword that pierced him contained reiatsu from every Gotei 13 member, but I don't think that means he has all of their reiatsu now (which is what it sounds like you're thinking).
It was more of a way to awaken his own dormant powers. Kinda like jump starting a car.
i know he doesnt have all there power but even a tenth of all of them combined would be insane but you are right it is probably way less than even a tenth but he is still really powerful right now and it leaves me wondering if he can still use his hollow form and or fullbring at the same time if so who can touch him