With his new method to absorb the red gas in crystal hearts faster, it didn't take long for Malachi to finish absorbing the crystal and turn it into a mere red crystal, just like the former crystal hearts he had exhausted.
Apart from his method to absorb the red gas faster, Malachi also knew that the reason he had finished absorbing the crystal heart was because it was of lower quality, actually the lowest quality crystal heart he had ever absorbed.
This was to be expected. It came from a zombie, after all.
From his experience, Malachi figured out that the quality of a crystal heart, in this case, meant the quantity of red gas it contained, depended on the monster it came from.
The one he had just absorbed came from the weakest of them, so it was not surprising that he was able to absorb it so fast.