Please take the "Hikki vs Ayu" fan war somewhere else. Seriously. It's always the usual trolls adding more fuel to the fire. *major side eye*
But on a serious note, I do feel that Hikki seems to lack technique with her vocals as of late. I'm a huge Hikki fan, as loyal as they come but I do feel that homegirl could use more vocal training. Also, maybe her change in vocals has to deal with the fact that she used to drink alcohol regularly (which she admitted to) heck, she probably still does for all we know. Alcohol has a tendency to dry out the vocal cords and cause a change in sound.
Agree to disagree and take my opinion with a grain of salt.