Malene has been a powerhouse ever since her release.
She has received nerfs but she is certainly not down.
When Malene is not banned she is almost always picked.
So far I have not lost 5v5 ranked when I have played Malene.
@Gatorrex has posted a video about AS vs AC showing their damage potential was the same.
However AS offers healing and Malene is the best AS user in the game because of her many skills.
Dark A is your aoe wave clear and best damage skill.
Light A is your root and safety skill.
light B is your movement speed boost+barrier for offensive safety or defensive fleeing.
Dark B is your get out of jail free card, dodging all incoming damage and effects after which you deal damage and your next basic will trigger AS.
Your C is a damage booster+form switch.
Weaving skills and basics make you a formidable force.
D-A C L-A L-B C D-B D-A is an example of a skill weave that allows you to trigger Aftershock a lot of times while chasing an enemy. Your C empowers your basics on top of aftershock.
AS-DE-CW is the best core build to stack DE and maximize skill damage but also creating a safety net through Light and Dark B. Between Light A Light B and Dark B you have 3 safety skills.
I believe she is still Overpowered or at least very very very strong and this is how you can utilize that strength when playing her.