I know I’m late to write about it considering the event started weeks ago. ^^; I just cleared part 2 of the event yesterday and working on the area that opens up in the bottom left of the map as well as completing the Crystarium.

Not much to talk about in terms of story since I didn’t even bother reading the dialogue. (And it’s not like I’d fully comprehend it anyway.)
Here’s some verbal diarrhea on the event basics and my experience!
The event map, known as Hanging Edge, is the usual with locks all over the place, but this time, you have to move to a second map – the Crystarium – to obtain the keys. In order to progress through the Crystarium, you need CP (Crystogen Points) which you can get from completing battles on the main event map.
At first, I thought SquEnix was going to have players grind for eternity to get CP but it turns out it’s not all that bad! You can quickly accumulate enough by simply going through the Hanging Edge normally as the amount you receive increases every few areas.

Aside from getting Crystal Keys for the main event map, the Crystarium also serves as the place to nab parameter upgrades for the Optima system.
Optima are divided into three categories: Attacker, Blaster, and Defender. You switch between them to gain boosts in attack strength, Break power, and defense respectively.
There’s a restriction for the number of times you can use each type in battle. However, the limit cap can be increased after completing certain areas in the Crystariums. (Part 2 has a second, different Crystarium map. All stat boosts from the previous one carry over~!)
You can technically traverse through most or all of part 1 without the need for the Optima on Normal gameplay difficulty with maxed out jobs but once you reach the later parts of part 2, you will encounter bosses that may kick your ass. Like the Manasvin Warmech pictured below.

The player encounters this enemy multiple times throughout their journey but this is the second last boss-type enemy in the second Hanging Edge map and it has been powered up BIG TIME. I was a fool and used Full Auto for the previous 3 fights so when I got to this, my Optima count was already low.
On Hard difficulty, which I was using at the time, it buffs itself with Wall, that reflect icon, and Barrier, I think, after its HP is at the 70% mark. They last for 13 turns. When you damage it, none of the buffs disappear; they’ll only reduce in the number of turns. This means if you’re in a situation like me where you have no Blaster Optima and a Break gauge is still present, you might as well give up.
I did after using 5 Phoenix Downs. XD And then I switched to Normal. It was still a pain to fight using my Strategist and the card set-up you see. I ended up using the Knight of the Round Table and was able to finish it without even making use of the Defender Optima.
Then came the battle after this which is a spoiler so I won’t comment on it other than “Ow”. On Normal, just using the Blaster – Attacker – Defender cycle works well since if you’ve completed most of the Crystarium, you should deal enough damage in 1 or 2 rounds to finish the boss off quickly.
Overall, I liked the double map gimmick and enjoyed the fact that immense amounts of grinding for unlocking paths wasn’t a necessity like in other events such as the Infinite Arena.
The Optima system is all right. It certainly serves as a way to get high scores! I beat my personal best several times already. 😀 I’ve never managed to reach 50 million before but I broke that yesterday! And then, about an hour ago, I got this:

Considering the top scores are in the 830+ million mark, I don’t see myself getting anywhere near the top 100 any time soon. ^^ I’m going to see how much higher I can get my score and then post my ranking on Sunday.
Edit on Tuesday, July 26th: Whoops. Forgot to update this post. ^^ The ranking range for these rewards is rather large. I think it’s 3001 – 15,000 or something. I usually manage to get a score that sits somewhere between those ranks.

The only complaints I have about the event are the size of the maps. I think the Hanging Edge and Crystarium maps in both parts exceed 60 areas each. Bleh. But for an event that’s going on until the end of August, it’s expected that they’ll be like that, I guess.
Correction: Lightning Resurrection finishes on September 25th Japan Time.
Oh, there’s also Lightning’s hair.

I’m using an iPad mini 2 and playing with HD assets. Maybe it looks better on more powerful devices?
Any idea how to get to those greyed out areas after beating lightning?
I’m reading at the Altema wiki that they’re guessing they’ll be accessible after the battle tower event.