I have been very concerned of Rahane's form and have even thought he should be given a break from the test side (not sure if I posted as much) but the captaincy seems to have reinvigorated him. Always felt his attempts to become this key LO batsman for India since about 2015 has been messing with his technique in the long formats and I would actually prefer if he did a Pujara and only played that format.
But as a captain, he seems to have obtained more clarity of thought when batting. I think he will go from strength to strength now. At least, I hope he does.
I also hope Virat lets Jinks handle the team a bit more on the field, (and Rohit in LO cricket) coz you dont need to be named captain to contribute your bit to the side and I think both Jinks and Rohit seem to be better able to handle youngsters and help them overcome pressure situations coming in, than Virat.