What is your favorite blue physical armoured unit?

It's hard to not pick Hardin, cool avatar, unique character, one of games top units

Are you asking for recommendations or looking for diverse perspectives? I like several of them for different reasons - Hardin as native distant counter tank with good balanced mixed bulk, Effie for wary fighter builds to slow down the game in a OHKO meta, winter Robin for general blue offense + armor march, and LA Lyn for all kinds of aesthetic reasons (but she's not on your list).

i'd say effie because of her flexibility but its really hard to say no to a prf DC weapon in Hardin

I adore Hardin and not just because he’s fantastic in battle. His reasons for being the way he is break my heart and I really feel for his character, so he already has earned my love. He in love with a woman who will never love him back, and that hurts me because I feel him.

Overall usefulness + merge potential: Effie and Wendy
Style: W!Robin
Base kit: Hardin
Free... That’s all this category has going for itself: LA!Eliwood

Eliw00t

Out of your candidates I pick LA Eliwood, since I enjoy using him, I leveled him up finally alongside Flower Sanaki as her bodyguard and they co-operated well! I wish I was swimming in Hectors so I could try DC on him. Gwendolyn comes as close second and can be built to a nice enemy phase unit, also suffers from a lack of DC.

I have an Effie I never got to complete, she was a little too meta (not anymore I suppose) to be interesting.

As for the remaining candidates, I got a Winter Robin whom I'm going to fodder as I don't like him and am not a fan of Fallen Hardin either, I don't know much about his character in the original game but in general I dislike the fallen heroes.

Definitely Hardin. DC prf weapon, and great mixed bulk? Sign me up. He's also no slouch in the damage department.