When Willo Ults, fly into the air as well to take her down. This makes it a lot harder for her to hit you, especially if you have good aerial movement.
dont try to hard to chase the Evie unless sh's very low and you have Kill to heal on. most of the time she'll lead you into her team when she runs away. when in a 1v1 gain height on her and force her ice block.
Tyra is very strong against you, in order to win this fight you'd either have to hit a head shot, hope that her aim is off or flank her with the best option being to flank her.