Aeron absorbed two more B-rank Haunt cores, though he didn't gain much powers from them this time due to him already becoming more powerful than the B-rank threshold.
Going past 50,000 in Spirit and Curse power meant that he was already in the realm of A-rank Phantom Hunters.
However, he was not as powerful because he hadn't developed his newfound power, which was the special trait of B-rank and higher Phantom Hunters—Soul Gear.
One could be considered a proper B-rank Phantom Hunter only if they had manifested their Soul Gear.
Soul Gear varied from person to person, acting as their personal weapon with unique powers that could bring out their full potential—however, the consumption of Soul Gear was high, so people only used it as their trump card.
After consuming the Haunt cores and making his Spirit and Curse power reach a bit over 70k, Lapis guided Aeron in awakening his Soul Gear.