Well, we can take Fordola as an example of what the Echo can do, combat wise. With heightened senses allowing all movements of an opponent to be heard and reacted to.

Then we have Krile as an example of non-combat effects of the Echo, allowing the sensing of other people's emotions.

We and Ysale show that the Echo can be used to look into a person's past and re-live scenarios.

Also, I believe lore-wise it allows us to see fairly far into a potential future (I.e. "Echo Bonus" in trials. We don't actually fail, we just see a potential future in which we failed and then use that knowledge to fight better) of course, not all the time, otherwise well that whole banquet fiasco could have been avoided...

This is merely just the Echo.

As the Warrior of Light, we also have Hydaelyn's Blessing, which allows us to do things such as survive Ultima (Also, strip Ultima of its primal power allowing us to overcome it), survive Midgardsormr, face Ascians without being tricked by all their jiggery pokery and what not (Though, that said, we did face Nabriales without the blessing when Midgardsormr removed it from us to see if we were worthy of having it), we even used it to pull Lahabrea out of Thancred.

Though, due to the actions of Midgardsormr and his removal of our blessing, some people theorize that the Blessing of Light is merely a shield to protect us and that our strength and capacity to do badass things is just something we're naturally talented at. Given that not only were we able to overcome the primals in the first place to GAIN the crystals for the blessing, but then when it was removed we continued to be a badass, albeit were susceptible to the Ascians doing Ascian things.

So take that for what you will. It suggests that the Echo has a lot of potential (If you want to refer to the original Japanese the direct translation is "The power to transcend") I mean, massively heightened senses, the ability to see into the past and future and all sorts of other crazy things that keep being added (Such as when we faced Lakshmi for the second time and could defend against her attacks, along with Arenvald and Fordola). While the Blessing is merely "Plot Armour" to allow us to essentially walk away from nukes without a scratch (But also using up a substantial amount of Hydaelyn's already weakened power...)