This is a wall, not only it blocks every visible rays, but this fact also completly weaken the champ.
J4 ulti is useless now due to mobility creeps, even 
can get through, my concern is why can people like 
get out of it because they pressed Q on minions?
LordForrest12 votesAt first i had no idea what the hell you were trying to say, but after hours of code breaking and reading the comments, i realized that you where asking for J4's ult to limit vision for champions within it to only the interior of the ult.
My thoughts on that are.
http://fullnomad.com/wp-content/uploads/2015/08/make-it-so.png
D357R0Y3R1 votesAt first i had no idea what the hell you were trying to say, but after hours of code breaking and reading the comments, i realized that you where asking for J4's ult to limit vision for champions within it to only the interior of the ult.
My thoughts on that are.
http://fullnomad.com/wp-content/uploads/2015/08/make-it-so.png
that would be broken af, 
is killing someone, then j4 ulti, ahri can no llonger see where the target is and can't land her skillshot
LordForrest4 votesIn response, you do realize that nocturnes ult basically is worse seeing as its global, removes ally vision, and reduces your vision. Graves W does this to any champion within the smoke. Quinns Q does this to enemy champions she hits. Its an established game mechanic already, just underutilized. Also your example is bad because as J4 ulting a Ahri with her ult up for any reason other then an execute is a waste. Hell, she can dash out of your ult, back into it, and out of it again.
The Bearded Bard1 votesNocturne's ult doesn't reduce ally vision, or vision for yourself.
LordForrest1 votesIt removes ally vision and reduces your vision radius for the entire enemy team. i.e. you can only see what around your champion specifically and it is reduced compared to normal.
Got New Glasses4 votesthat would be broken af,
then ahri would just get out of the wall
Crossette4 votescan no llonger see where the target is
K.
can't land her skillshot
IF THEY HAVE A BRAIN THEY CAN
ACENOX1 votesAt first i had no idea what the hell you were trying to say, but after hours of code breaking and reading the comments, i realized that you where asking for J4's ult to limit vision for champions within it to only the interior of the ult.
My thoughts on that are.
http://fullnomad.com/wp-content/uploads/2015/08/make-it-so.png
yea, sounds a good idea,
The Bearded Bard9 votesUseless ult? It's a dash that does quite a large amount of damage and can be used to force spells, split teams in half, isolate a carry, escape, clump their team for your team's aoe, peel for your teammates, and of course ensure an enemy can't escape.
It's extremely versatile and far from useless.
Ahristocats2 votes[{quoted}](name=The Bearded Bard,realm=NA,application-id=3ErqAdtq,discussion-id=XcLneYFI,comment-id=0003,timestamp=2016-01-08T11:56:21.678+0000)
Useless ult? It's a dash that does quite a large amount of damage and can be used to force spells, split teams in half, isolate a carry, escape, clump their team for your team's aoe, peel for your teammates, and of course ensure an enemy can't escape.
It's extremely versatile and far from useless.
isolate a carry? not only they have mobility, but they also have 
to save them, j4 due to a lot of new champs since 2011 had been weakened really hard, 
can just ulti and wait until your ulti finishes.
and with all the mobility, peeling for your teammates, blocking an enemy is tought now, but if you add this change, peeling for your mate will be done, because they can't see where your mate went and some can't escape the wall because they need to see a target to escape
DorkunedAuras1 voteshow does braum save them from J4 ult?
KONO RUBICK DA1 voteshow does braum save them from J4 ult?
jump into them--->ulti to cc j4-->wall --->the adc is safe from projectiles which is 90% of league damage
DorkunedAuras1 votesThat's different from Tahm or thresh who directly pulls them out of the wall.
KONO RUBICK DA1 votesThat's different from Tahm or thresh who directly pulls them out of the wall.
but it still invalide j4 ulti which should isolate a target, and since j4 blocked his team, nobody can get past braum
The Bearded Bard1 votesYes, J4's ult was 'invalidated' by another champion's ENTIRE KIT. You used your ult, W, and E to stop his ult, and it wasn't even effective considering they're still trapped, J4 has no projectiles, and you didn't stop the damage from J4's ult.
The Bearded Bard1 votesThis just in: 
's ult is useless because GP can use his W to get out of it and everyone else can use their teammate's CC.
If you're that worried about people using mobility to get out of it, wait until they waste their mobility spell, then use your ult.
KONO RUBICK DA1 votes[{quoted}](name=The Bearded Bard,realm=NA,application-id=3ErqAdtq,discussion-id=XcLneYFI,comment-id=000300000001,timestamp=2016-01-08T20:45:55.962+0000)
This just in:
If you're that worried about people using mobility to get out of it, wait until they waste their mobility spell, then use your ult.
yes, but malz is only countered by few, like gp/olaf/ali, j4 is countered by 80 champs, waste mobility spell? rofl riven has 4, lee has 2, and don't forget flash
The Bearded Bard1 votesHe is absolutely not countered by 80 champs. Just because they can use a spell to get out of his ult, doesn't mean he's countered by them. By that logic, Ziggs is countered by every single one of those champs as well.
Those champions counter J4. The rest either straight up don't, or break even.
KONO RUBICK DA1 votes[{quoted}](name=The Bearded Bard,realm=NA,application-id=3ErqAdtq,discussion-id=XcLneYFI,comment-id=00030000000100000000,timestamp=2016-01-08T21:59:30.709+0000)
He is absolutely not countered by 80 champs. Just because they can use a spell to get out of his ult, doesn't mean he's countered by them. By that logic, Ziggs is countered by every single one of those champs as well.
j4 can't do shit about those two, and it's just some example, also makes j4 wortheless because he stays close to his adc if he get knowed up/ ultied he eats him and wait for the ulti to finish
LaoBushido3 votesYour title is confusing, The mechanic that prevents people to use dashes through a created unit such as with Azir's ultimate did not exist at the time of Jarven's creation. Should he get a rework at least on a juggernaut scale this might be changed. I personally think this gives him a lot of counter play . However it should not be used on someone who can get out of it in the first place unless they are low hp such as anyone with a dash, blink etc.
KONO RUBICK DA7 votesYour title is confusing, The mechanic that prevents people to use dashes through a created unit such as with Azir's ultimate did not exist at the time of Jarven's creation. Should he get a rework at least on a juggernaut scale this might be changed. I personally think this gives him a lot of counter play . However it should not be used on someone who can get out of it in the first place unless they are low hp such as anyone with a dash, blink etc.
op isn't asking for j4 to have azir ultimate, but to limit the vision of the units inside j4 ulti. This would prevent some champs to escape his ulti 
and it would give him some utility
RISE Shlack1231 votesWell, that's kinda what the OP was saying - more and more champions have mobility, and J4 becomes less and less useful. If you're J4 and you ult Lucian, for example, Lucian only has to burn a low cooldown ability to escape your massive cooldown ult.
While I agree that champions having dashes adds counterplay, I contend that too many champions are able to counter J4 by simply existing. I do agree that the ult should give Nearsight, meaning champions like Yi and Talon can't just target someone outside the cataclysm to get away easily. They should have to burn a mobility spell or flash, IMO.
Spoofghoul1 votesYes i like this idea even tho i dont play Jarvan myself i think this is a very easy solution to ''fix'' the ultimate.
elon wątroba1 votesSo fucking nice idea
PDE5 Inhibitors1 votesSo you want it to be like Graves thingy?
Taric the Gay1 votesIt's actually not a wall. The outer perimeter "falls away" leaving what looks like lava filled crevices around the perimeter of the circle. There are no walls, sorry to inform you of this.
KONO RUBICK DA1 votes[{quoted}](name=Taric the Gay,realm=NA,application-id=3ErqAdtq,discussion-id=XcLneYFI,comment-id=0006,timestamp=2016-01-08T16:41:17.095+0000)
It's actually not a wall. The outer perimeter "falls away" leaving what looks like lava filled crevices around the perimeter of the circle. There are no walls, sorry to inform you of this.
wall: definition: a vertical construction made of stone, brick, wood, etc., with a length and height much greater than its thickness, used to enclose, divide, or support .
LordForrest5 votes_Cataclysm is a single target dash that creates an impassable wall around Jarvan when he lands. _
Just going to leave this here.
Quepha1 votesbecause everyone on a team shares vision unless you have been using j4's ult to NOT trap enemies inside of it.
Z Statistic1 votesnot sure how I feel about this. It might lead to ridiculous shit until it's removed or nerfed significantly like Graves' W.
