Slow the attacker, knock them up to interrupt them, shield the carry.
Janna Wild Rift Expert Guide
§ 07b — Advanced MechanicsJanna: combos & tips Wild Rift
Flash behind the enemy group, use Monsoon to knock them back towards your team or under the tower.
Zephyr slows the enemy; auto-attacks capitalise on the slow to trigger the bonus damage.
Charge up Howling Gale in a bush, then release it towards the enemies for a surprise knock-up. The more you charge it, the more damage and knock-up it deals.
FAQ
How should I play Janna in Wild Rift?
Janna is generally played as Support. The first objective is to priority vision/roam short when wave is neutral. Its biggest edge comes from disengage reference.
When is Janna strongest?
Janna takes over in mid game: groups of 2-3: protects the win-con tool (adc or mage).
How do I punish Janna?
Janna can be punished when very dependent on her cds. A practical answer listed here is: Forces his defensive R, then re-engages with TP/zone ultis when in CD.