Dude sorry to say this but all service based companies have boomer managers.
Why do they have boomer managers and mediocre?
Because these people are incompetent and most of them won't be able to get a job in product based companies.
Why is he cold?
Because ever since he started working in the IT sector he had a toxic managers,check his LinkedIn profile I am pretty sure he is from mediocre companies.
And he thinks acting cold towards you just because you ask for leaves is normal (Because it is out of the ordinary for him. )
I am pretty sure he thinks "how dare this guy ask for 10 days of leaves,when I was his age I used to work for xx hrs ,never took leaves for more than 3 days etc" Just because he fucked up his early days doesn't mean need to fuck up your 20s as well.
This is called the boomer uncle's mindset.
Boomer uncle managers/employees are generally toxic.They don't respect your space.
They think they are older and can say and do anything to you, since you are younger(that's how our Indian culture is dont question the elders[this stupid]).
I worked in Accenture as well.Most people I met had a mediocre mindset [no drive to achieve anything ]and toxic managers (also met great people as well).
I quit accenture without any offer in hand(best decision ever) now I work as an ML engineer.
My suggestion to you is : plan your exit,evaluate interviewers as well when you are taking interviews.Dont get into companies with boomer mindset people.
Do your job get paid until you leave the company.I am pretty sure this guy will make your life hard for months to come.(I hope not).Try not to ruin your relationship with your manager.Deal with him somehow and leave this service based shithole company.
I will stop yapping now.