Shen or Shyvana

Shyvana is superior in my opinion. She is in meta. She is amazing with devourer in jungle currently. Her passive adds double "natural" armor&magic resistance when in dragon form. She can carry games and adds a lot of team fight pressure to focus her instead of her carries because she does fast damage with life steal that she should have (BORK) Plus she is a Dragon! What else do you want?!

Completely dependent. Both on playstyle and in team comps.

However, the most usual team comp would want a Shyvana over a Shen more, so I'd say get her.

you wanna fck up their health bars? get shyv you wanna fck their nerves? get shen ( DAT FCKING TAUNT NOOB SHEN bleh bleh incoming if u do it)