Answer

Khan could sense that his body suffered when using the [Blood Shield] at full power. He used the check-up technique while the clotted blood vessels covered his arms, so he could see how quickly some important organs deteriorated while the alien ability was active.

Khan had to disperse the technique after a few seconds to avoid facing drawbacks. He took a few deep breaths as he unfolded his sleeves and calmed down. He would need to perform a few tests before using the [Blood Shield] in an actual battle, but he felt satisfied that the procedure had been a success.

"[So, you have improved the overall sturdiness and extension]," Caja commented while Khan calmed down. "[Still, the burden that your body has to carry to activate the technique has also increased. You might end up killing yourself if you aren't careful]."

"[These arts carry great danger]," Khan revealed, "[But they also grant great power]."