Windies ran out of gas at the latter stages of the ODI series, crumbling to 104 a/o, Jadeja grabbing a 4fer. India hunted the target easily 105-1 Rohit 63* and Kohli 33*. India's sixth consecutive ODI series win at home. You've gotta be pretty decent to turn them over on their own patch. IIRC the last team to win in India was South Africa and that down to a de Villiers master class in the deciding match.
Kohli finishes 2018 with 1202 runs at 133 with 6 centuries, had he not skipped the Asia cup he might've got near Tendulkar's 1700 ODI runs in a calendar year and 9 centuries.