Definition of Yoga as Defined by Bhagwan Shri Krishna in Bhagwad Gita Chapter 2 verse 48 is
योगस्थ कृरु कर्माणि सङ्गंत्यक्त्वा धनञ्जय | सिद्ध्यासिध्यो समो भूत्वा
समत्वं योग उच्यते||२.४८||
Yogasthakuru karmani sangam tyaktva dhananjaya| siddhya-asidhhyoh samo bhutva
samatvam yoga uchyate||2.48||
Abandoning attachment and established in Yoga, perform works, viewing success and failure with an even mind. Equipoise is said to be Yoga.
Commentary by Bhagwad Ramanujacharya :
Abandoning the attachment to kingdom, relatives etc., establish yourself in Yoga, engage in war and other such activities. Perform these with equanimity as regards success and failure resulting from victory or defeat which are inherent in them. Yoga is defined in this verse as "equanimity with regard to success and failure.”
So formally Yoga is defined in this verse as :
Samtvam yoga uchyate or "equanimity with regard to success and failure."
My question is about the Characters in Mahabharata and most known people who were present in Kurushketra war whose behaviour was such that they are fit to be known as yogi according to this definition.
For E.g. Yudhishthir was every time in yoga because irrespective of situation good or bad he was always following Dharma as in Dharma Shastras, without a second thought so he can be a yogi.
Bhishma on the other hand was trapped in his own karma (words to different people) and was not following dhrama even thought he knew it , it means he didn't have a sama buddhi to analyze the situation and thus he was not fit for the title of yogi. etc etc.
PS: If this question is too broad to answer let me know in the comments section I will edit the question and restrict the parameters of analysis (characters).