Luden's Echo Clarity of Tooltip and Thoughts on the item
Luden's Echo, the new 120 ap item brought in to fill the void of the Deathfire Grasp in terms of ap itemization. I don't feel like this item fills Deathfire Grasp's niche (A niche Riot clearly wants to go away) but is a step towards more and better ap itemization. There are some things worth mentioning with the item. Weird interactions, Who might be the best use for it, and who might be some overlooked sleepers with this item.
However the first thing I want to mention are a few weird interaction that may or may not be intended but I found weird. Bard's passive Meeps proc the effect. This seems strange since the items says on next spell cast. I would hardly call meeps a spell. Ezreal's and GP's Q do not apply the effect which seems very odd for at least Ezreal. I can understand not wanting to support AP GP as a side build but AP Ezreal has always been a side build for him and not procing from his Q does seem a bit odd since it's his main spell. These interactions point to an inconsistency of clarity regarding the wording of the item. The item clearly states on spell cast.
Now this leaves two options to clarify. Either state that the spells must deal magic damage or reclassify Ezreals and GPs Q's as auto attack modifiers. Yasuo's Q specifically says that it is a skill shot basic attack so there is an option to state that these are just modified auto attacks or are they spells.
My personal thoughts on this is that Meeps should not as GP's Q should not. The reason I think Ezreal's Q should proc over GP's Q is that Ezreal has always had that AP build side path where as AP GP has always just been considered a trolly build.
The next thing I'd like to mention is that on dominion or twisted treeline Needlessly Large Rod is not purchasable so if you want to buy this item on Dominion you have to wait a long time with nothing to show for it. If you want to leave this item on Dominion and TT it really could use a new recipe. Maybe something like Blasting + Blasting + Ather Wisp + ( Old Combine - 120g)
Now as for the item itself. This item with it's stats should find it's way into peoples builds especially for non mana using champions. Only one item provides more %move speed than it (Zephyr being 10% move) which helps low move speed mages. 120 AP a huge chunk of ap. The passive provides a tinge of wave clear for the mages that desperately need some. In a vacuum this all sounds great however, combine them all and you run into some interesting best cases.
Ahri and Katarina come to my mind. Now take this with a grain of salt when I say I havn't played Luden's Echo Ahri. I can see how she can cause a problem her kit has a lot of spell casting and mobility. The added move speed + extra clear and damage + huge chunk of ap makes her uncatchable and highly damaging. Katarina I have played. She still suffers from her standard CC me and I'm doing nothing problems. Luden's Echo allows her Q to clear a wave basically by its self at a much lower ap. Adds some more burst to her ulti. Shunpo charges it 20 + distance moved. This item adds so much to her.
Though those two are obviously the front runners for best usage of Luden's what about others? It can play a role in any mid laners arsenal as a huge ap item but I don't feel it out shines other picks. I feel like people will still build torment and other items over this. The proc just doesn't seem to add much damage you need 667 ap just to make the proc deal 200 damage and the proc isn't up very often unless your a spam heavy caster that moves a lot.
I haven't played a ton of champions with it yet but for the experimental few of you out there I'd recommend trying it out on Rumble. He moves a lot, casts a ton, almost always has the proc up thanks to his combat style, and any tick of his flame spitter procs it. The move speed and huge ap benefit him greatly and the proc, while maybe not the hugest burst source, does add a bit of surprise to his damage. I feel in the long run this item would out damage Torment by quite a bit. If you don't need to hp pick it up and give it a try.
Another recommendation is AP Zac. He slingshot coupled with his chase and slow play style make him fall into a category like Rumble. He'll have the proc up a lot and will add a tinge of burst to his kit plus help him wave clear. I'd only recommend this if you're more experimental.
Some more champions that you may want to try Luden's on include Akali, Bard, Diana, Fizz, Kennen, and Sona.
Overall, I feel like Luden's is a great item. It doesn't fill Deathfire's burst role but does add a little burst and wave clear as well as being a huge ap and movement option. While some champions will use it to great effect, on some champions it might not even be built. We'll have to wait and see who uses it best out there in the fields of justice.
Things left to test: Veigars Q seeing if the Luden's proc adds AP from his Q Luden's kills from a Q proc