The continuous reduction of Life should halted with the worst
wound healed, but Eugeo couldn't use any luminous-type sacred
arts capable of recovering Life of someone who lost much of
theirs. He grasped Kirito's right hand with his left without any
hesitation and chanted a new art ritual.

“System call! Transfer human unit durability, self to left!!”

Beads of indistinct blue light covered Eugeo's entire body this
time around and they immediately gathered at his left hand, then
streamed into Kirito's body. This art which allowed for Life
transfer between humans had a huge effect despite the art
ritual's simplicity.

Thinking back upon it, Kirito was the one who had suffered
heavy injuries while Eugeo had barely lost any Life, both during
the battle against Deusolbert and this time as well. He couldn't
possibly pay it all back unless he handed over his Life to the
brink of collapsing.

Or so Eugeo thought, but when he felt roughly half of his Life
had finally flowed out, Kirito fuzzily opened his eyes and gripped
Eugeo's hand with his left, pulling it away from himself.

“...Thanks, Eugeo, I'm alright now.”

(Alicization Rising, 268)