
Personally I would suggest re-reading especially since we basically only have one more chapter which is the author discussing about the webtoon and thanking their fans for their support.(▰˘◡˘▰)
But since you asked here goes....... Spoilers for those who are NOT caught up with the webtoon....☜ (꒡⌓꒡)
It's been awhile since I read this so my explanation may not be ENTIRELY accurate but from what I remember when I last read this webtoon:(⊙…⊙ )
So yeah Chi Hwan is no longer a vampire Σ(っ°Д °;)っ after the fight with Chi Hwan's (previous) ex-link their was a fight between Chi Hwan's ex-link and Soohin's non-friend turned vampire due to getting himself stabbed by Chi Hwan's previous link resulted in Soohin almost dying.
Though both the ex-link and non-friend died at the end of the fight, but due to Chi Hwan overexerting himself and from Soohin getting stabbed by the ex-link ヽ(`Д´)ノ ╥﹏╥(prior to both of the ex-link and non-friend's deaths) Chi Hwan desperate to save Soohin turned him into a vampire. But because Chi Hwan overexerted himself and also probably as a side effect of his link's death, it turned him back into a human. Σ(  ̄□ ̄||)
When Soohin wakes up Chi Hwan is a human and he is extremely weakened and ends up coughing blood after saying some sweet words he becomes silent causing Soohin to burst into tears and what seems like a bitter farewell(✿˃n˂ ) Soohin at that moment realizes he is a vampire.( ・о・)
If I remember right because some of the blood on Chi Hwan was from Soohin's non-friend during the fight Soohin gets flashbacks of BOTH Chi Hwan and his non-friend. From them he realizes he is a vampire and that he can save Chi-hwan and turns him into his Link saving his life.(ノ→ܫ←)ノ
Wait so, chi hwa is not a vampire anymore? Is he no longer an immortal? (Please share I skipped to the last chapter :'') )