The power of every spell had increased by roughly 50%!
Such an incredible increase was possible.
Only because the spells being enhanced were low- and mid-tier.
For spells of the sixth or seventh tier, or even higher, Xiluo would not have been able to achieve this effect.
After all, the heart's original owner, Manoen, had only been a level-eighteen Abyss Demon.
The spell and Breath Weapon he had just used were equivalent to second- and fourth-tier spells, respectively.
They had consumed about 7% of the heart's fel energy.
At this point, perhaps because fel power had been consumed, the entire Fel Energy Heart began beating considerably harder than before.
Xiluo distinctly felt some of the life force inside his body begin slowly flowing into the Fel Energy Heart.
This did not surprise him.
Fel power was an extremely unusual, violent power.
It was a violent power obtained at the cost of burning away life.
With some of the fel energy in the Fel Energy Heart consumed, it naturally needed replenishing.
Xiluo tried to stop it, but found that he could not.
At most, he could reduce the life force flowing into it...
There was no point in that.
He simply let it absorb freely, and after several minutes.
The Fel Energy Heart was full of energy again.
As for how much lifespan Xiluo had lost, he himself did not know the exact amount.
After all, dragons were a race with lifespans of thousands of years.
And with three mutated dragon bloodlines, his lifespan would only be longer!
An ability that was deadly poison to humans was nothing more than a light drizzle to him.
Turning to glance at the cleric, Xiluo asked:
"How many years of lifespan does it take to refill this Fel Energy Heart?"
"In terms of human