Barrier
Sucks.
Sucks.
Barrier.
Used to counter ignite, and has a lower cooldown of a summoner spell, so trading spells is worth with it. You can use it while CCd so it can be helpful in situations where heal isn't.
Very limited situations that really don't help at all, you need reaction time and 2 seconds on the durations is really bad. Heal almost gives as much heal and its effects are permanent for you AND your team. 10x better. Barrier sux