Break the meta - Irelia support
How is she viable as a support?
Irelia has a kit that can lock down a certain champion. Her e can stun an oppoent when her hp percentage is lower than the target's. As a melee support, Irelia will definitely be taking some harrass from the enemy ADC, so she most likely will have less hp percentage than their ADC, guarenteeing a stun when an all in is initiated by either sides/ganked and need to escape. Her e is extremely useful in different situations and at times can allow outplays to happen when e is maxed with its 2 second stun duration. After laning phase, you will become the true protector of you ADC as your utility will come to great use. With full CDR, her e CD is pretty short, allowing it to be used multiple times during an average teamfights. This allows you to maximise your effect in fights as you can land stuns on targets that threaten your team or adc the most.

She also has great gap closer, with her q resets. This provides you with mobility and higher chance of landing stun than e.g. taric's on enemy adc. Your passive (tenacity that scales with number of enemies) also ensures that you can be active in fights longer and do as much as possible for the team.

Pros:
>reliable stun with short cd into mid game
>protect and peel for ADC
>Lock down enemy threats
>help ADC melt down tanks with Hiten Strike(W)
>Gap closer

Cons:
>Squishy early game,gets harassed a lot and cant do too much in lane other than warding and landing stuns in all-ins
>Item reliant, really need the tankiness and item passives to be effective
>Stuns can be hard to land if not familiar with how it works