I played Marci as offlane for quite sometime now but after 7.31b PB release, Valve nerfed her too hard to the point she can't go 3 anymore.I understand they wanted her to be played as support if that's their intention. So I shifted my role as 4 and 5, I've also have decent hero pool for support roles in case Marci is ban, I'd pick Shadow Demon, Crystal Maiden, Dark willow, etc. I love this hero so much, she just fit to my playstyle because I'm playing aggresive all the time.
The problem with her as support is after laning phase she just become less effective compared to other supports who provide more in teamfights (ex. Rubick, Enigma, Shaman, Dazzle) .She's too vulnerable when warding because she's a melee hero and have 0 escape when isolated warding alone is like deathwish for Marci, she's slow at stacking neutral creeps, atleast my shadow demon can stack 3 camps at the same time, She can't farm getting blink dagger with her always takes 15 mins just to be able to have effectiveness in teamfight.
There's just nothing I can do to make her work I tried every possible ways just to make her a good support, giving salve to carries, never tried taking camps or creeps just so my carry can farm, always ward and deward as fast as possbile. but always ended up getting outshine by other hero supports, that's just how terrible she is right now. Maybe it's just about the drafting or my teams poor playstyle, idk anymore. But I love this hero so much I just hope valve will do something about it in next patch I'm not asking for huge buffs or anything just make her a decent hero again.
Source: https://www.reddit.com/r/DotA2/comments/v3iwuy/sad_current_state_of_marci/