Hearthpwn

I think questioning adventurere and neon gave good advice, i will just add to what they said.

Firstly if you are playing ranked unless you are one of THE top players you will go up and down the ladder and average something pretty close to 50% win rate.  With this in mind you could get heads 100 times in a row from flipping a coin but it is very, very unlikely.  But i think you are just saying you want a competitive deck.

From what you said it sounds like you like control, warlock and priest are the typical top control decks i would say.

Also, as rule of thumb aggro decks focus on their goal of killing fast whereas control just try to stay alive and then kill later.  This makes control decks more responsive to what the opponent is doing rather than just focusing on themselves, this means you need to know the meta well to know how and respond.

Having cards that can be versatile sounds good in theory but sometimes you just need an ordinary knife, not a swiss army knife.  I find adapting your play style to the situation is more effective than having adaptable cards.  For example even if you are playing a mirror match depending if you are on the offensive or defensive will determine your play style. 

Ranked meta is just a form of evolution with climbing the ladder the equivalent to survival of the fittest.  Pretty much every combination of (playable) cards will have been tried, the successful decks will climb.  This makes it unlikely you will make a completely original deck that is competitive.  With that being said even slight tweaks to decks or playing style can completely alter a game. 

To give you an example, i play secret mage and went online to compare my deck list.  There are many variations on the deck but i would say  there are about 25 core cards.  From grinding and using deck tracker i can tell you around ranked 5 there are 3 main heros used:

Paladin 25%

Mage 28%

Warlock 20%

(Priest 12%)

(the others are pretty negligible)

Of these 3, i have about a 50% chance of winning vs warlock, 60% vs mage and 30% paladin.  So i have focused on improving my odds against paladin. I used to run firelands portal and briefly tried pyro blast but so often i found they were just dead cards similar to other 'finisher (7+)' cards used.  I would get beat down turn 5-7 by paladin or it wouldnt make much sense playing when i have have aluneth down and other cards that are more cost effective (and card advantage is no objective). Instead i run a volcanic potion, second- rate bruiser and frozen clone and have had found them very effective.  I got to rank 2 last month, will try getting legendary this month. 

So whilst the deck is 90% typical secret mage 10% is my take on it and this is what makes it my home brew.  Of course, the lower rank you are playing at the more deck variations there are and you can get away with more.