Questions of whether or not the viva will be “easy” or “hard” are unanswerable. There are too many personal and subjective factors. Objectively, we can say that the viva is a challenge. The level of the conversation, the nature of the discussion, the purpose and hoped-for outcome – all give rise to an environment of challenge.
It could be a challenge to respond to critical comments, but in the moment you find it easy to reconcile your examiners’ words.
It could be a challenge to recall specific details of something that would ordinarily be trivial to remember. You might need to pause, check your thesis and see if you can find something to spark your memory.
Don’t expect easy or hard. Expect a challenge.
And expect that by now you have a talent for rising to meet challenges.