How to restore my phone, after replacing my systemui with a modded one? I recently saw a thread about a modded systemui on XDA here and downloaded it. I replaced my present systemui with this  one and rebooted my phone. I think that at first the replaced systemui didn't work so I got a systemui-less experience  (You can learn about my experience by reading the comment I made on SO here ).

Then I learnt that I hadn't set the permissions rightly so I changed the permissions of the new systemui to 644 as said at XDA and rebooted my phone. 

After the reboot my apps were optimized as it happens after an update. But this time the new systemui worked  (probably) as I now have an all black screen after my phone boots normally. 

I then tried to enter into recovery mode and wiped the data (factory reset option) and booted again, but that was of no use as the problem persisted. 

What can I do now?  Will I have to go all the way reflashing my phone? Could anyone suggest a better option as reflashing seems to be the last option for me. Thanks in advance. 

Phone model: Lenovo Vibe C, 16 GB variant, currently running Android Lollipop.

EDIT 


It was all my fault as the mods were meant for Samsung galaxy alpha (I did not read the title at XDA before messing up)
I don't have a custom recovery installed nor do I have a NANDROID backup made before. I'm completely helpless.
Your best bet would be downloading your stock ROM from online, take the SystemUI.apk and put it back where it should be.