A beautifully written and marvelously created fantasy historic drama  that is worth each second watching and savoring.Story:A marvelously woven fantasy that builds on reincarnation, portraying a friendship strong enough to span centuries. The message behind the story was so epic and majestic, it just brings an already highly entertaining and beautifully shot drama to a whole new level of perfection.The story portrays two timelines, with the present one in focus and the past one as recollections and flashbacks. The past arc, 1930s Korea under the Japanese rule portraying the comrades fighting under the main goal of liberating their homeland , the present arc modern day Korea,  destiny and fate playing their divine role bringing together the reincarnations of the comrades.I Loved how both the past and present arcs interwined seamlessly making the viewer sometimes mistake a present character for his past self, and feeling the consequences of past events that took place during the past arc in a way that is raw and immediate like it both involves and affects our present-time OTP.CastHighly solid and believable performances by the main leads especially from the ever-young Yoo Ah In. I might have had my doubts initially concerning the female lead's casting choice, and felt that she didn't really fit the role, but later on when the story developed and the past-time arc was portrayed more I started to feel she fitted just nice, and Im Soo Jung's overall performance was excellent.As for Go Kyung Po, I really enjoyed him when he was being funny or goofy, not so when he was emotional and melodramatic, I have to admit that as originally an actor who excells in the comedic genre, he needs more experience on emotional portrayals. But beyond doubt, his not free of flaws performance were never distracting or cringe-worthy.The characterization:All characters felt believable, and I really appreciated how the child traumas in both of our present-time OTP's lives which greatly shapes who they are as adults (such as abandonment and betrayal) is not excessively shown with endless flashbacks like other dramas do, rubbing it till the viewer gets sick, but rather they're first introduced at the exact right moment in the story after several hints, and afterwards is only refered to in conversations.Out of all the characters, the main lead felt the most relatable and believable, showing multi-layers of personality, in a sense 3 dimensional. Like how their behavior changes drastically when they open up to people, and how the character they show to the world is a mere facade or defense mechanism they developed as a result to their past traumas.No need to mention, that as usual I appreciate drama-writing which gives characters a sense of their feelings, and not act dumb when they harbor feelings of attraction to someone, but rather own up to it, and act accordingingly while being true to themselves.I might have not been equally invested in some other characters' lives and odd choices of behaviour (like the ever so passive writer Baek Sr. and his evil wife with a never-ending vengeful agenda) but it was strangely convincing that such oddballs can only bring up a Sociopath psycho freak that was Baek Tae Min.                 The script and direction:The story had a very original take, and stayed true to it all through the drama, never going astray to the main message it aimed to deliver. As a person who is not so much huge fan of history or politics, I liked how the past arc was focusing on the friendship and camaraderie of the fighters rather than the mechanisms and specifics of their fight. Above all, the pace of this drama was so good, there was no moment at all where you felt the story was dragging, and not one event or scene that felt unncessary (ie no fillers).The script was very strong and heartfelt, especially in the main trio's concersations together whether past or present, you were always smiling lovingly, tearing up, or getting inspired by their deep thoughts. The direction and cinatography was flawless, amazing props especially in the past-time scenes and open-space shots were always top notch.To sum up, this is a drama that once I finished I had a huge grin on my face, and rushed to MDL to add as an all time favorite.