Poke mages
Poke mages like Lux or Brand force Janna to constantly use her shield, completely breaking her ability to protect at the right moment. Their constant pressure prevents her from playing around timing. Additionally, they can hit from range without exposing themselves to her Q, greatly reducing her defensive impact.
How the champion adapts. Play more defensively, save shield for real bursts, and prioritize vision to avoid poke zones.
Sustain supports
These supports don’t look to engage but to win trades slowly. Janna cannot punish this playstyle effectively due to her lack of offensive pressure. Over time, she gets outscaled in sustain and loses control of the lane.
How the champion adapts. Accept a neutral laning phase and play for scaling and teamfights.
Explosive engage
Some engages are too fast to be stopped in time, especially if Janna does not anticipate them. A Leona or Pyke can create a window where Q arrives too late. If Janna misses a single timing, the fight is instantly lost.
How the champion adapts. Pre-charge Q and play around enemy engage angles.