Ivern's winrate is nuts, we can't argue that. Simply, my only issue with him is how closely he survives everything because of how low the Triggerseed's (E) cooldown is, as it's a shield that also slows and damages. Important to mention he builds alot of CDR naturally: 
(+ Intelligence mastery). The nerf I suggest is:
Triggerseed (E)
Cooldown: 12/11/10/9/8 -> 14/13/12/11/10
Nanuk Pihoqahiak16 votesI think they should start by making it so popping the shield disables the explosion damage and slow. It's sort of a lose/lose to not only have to eat through a shield, but be punished by a slow and extra damage.
An Undead brat5 votesAlso agreed.
Azteryz3 votesthats a great point
its like if sions shield was destroyed before he popped it he could still get the explosion hp dmg off, if i destroy your shield i should be rewarded with you being unable to use the shield other effects (dmg/slow)
this and the op's suggestion is a good start riot
Glory ln Death1 votes
How about we let him keep that ability... and, I don't know, maybe, let other shields function like that, too? I mean, it's only fair, right? I'm just stating the obvious, here!
Chromatic Eagle1 votesDo you think all shields need to function like Ivern's, or that all should function like Sion's?
Glory ln Death3 votesWhile I would enjoy Sion's shield functioning like Ivern's, it's probably better if they all functioned like Sion's.
Oelyk1 votesTBH, Sion can reactivate it early, meaning that he can choose to use the shield effectively and before it breaks to pop it, Ivern has no such way to trigger it early.
Food for thought, cause honestly without trigger seed explosion thats like half his damage and cc is gone.
Nanuk Pihoqahiak1 votesThat's fine and dandy. However, Ivern can spam his shield as it's 8 seconds base at max rank. This is before all of the support items he builds which easily brings it down to 4.6 or w/e.
MissingKayo5 votesWhat if the buff left behind could be picked up by anyone? So if Ivern/his teammates aren't careful, enemies could steal it anyways.
An Undead brat1 votesInteresting, but I feel like it wouldn't affect gameplay that much (maybe more in higher elos because they could place a ward to the Red buff/Blue buff-River bush and see the outer line of the buff pickup range and it would reveal Ivern's location) or might be pretty clunky to play around...
Skins Project1 votesI think it'd just affect his invades.....
Instead of denying them a buff your rather just denying gold/xp..
EndlessSorcerer1 votesI'd rather the buff not be duplicated.
Just let the buff drop on the ground and someone stand on top of it for a second to pick it up (like Rift Herald).
ChaddyFantome1 votesWhat if the buff left behind could be picked up by anyone? So if Ivern/his teammates aren't careful, enemies could steal it anyways.
I actually think this should 100 be a thing.
Mighty Mortein4 votesI just want Daisy to start its cooldown after death and not when Ivern Spawns it/her. Because if you're smart, you'll keep her alive for a while and have a small window to not worry about a Braum-like ult.
Rman1273 votesI feel like the sharing of buffs needs to be nerfed in some way form or fashion
An Undead brat1 votesAgreed it's pretty powerful for a team to have the same buff thrice potentially with the enemy side's one (if I didn't miss anything and it really is possible, otherwise read this further as if I said twice). It should be possible to make it so Ivern can share a buff only every ~third time he releases one/one is killed by his teammate.
Skins Project1 votesWhy stop at three!
Four buffs is the way for me!
SpecterVonBaren1 votesWhy don't we just make it so there's no reason to pick him over any other jungler at all? Let's get rid of his ally dash on Q too then and make him as generic a jungler as possible.
Rman1271 votesIf you're being serious, i have no faith in humanity's chances of intelligent life in the future if you are allowed to reproduce. If you're trolling, haHA.
SpecterVonBaren1 votesI am completely trolling with my previous statement.
Lùmen2 votesBrushmaker needs to last less time when spawned on top of epic monsters.
An Undead brat3 votesNice addition, good way to adress Ivern, too, I'd say. If not because of winrate, sure because of how frustrating it is to face.
Steelflame2 votesActually they said they are just going to remove the ability to hide an epic monster via it. It's an unfair advantage and is being removed. You can still use a bush to block LoS, but no hiding any more. I think it will be put through the next PBE cycle IIRC what the rioter said correctly.
Glory ln Death1 votesIt's coming to live tomorrow.
astralwit2 votesI hate him for his counterjungling most of all.
arans2 votesCool, let's go ahead and nerf that so Ivern literally has nothing at all. God knows those tree branch slaps are pretty lethal.
xJLx MCHammer1 votesNot that I mind the nerf, nothing but this champion is literally a support jungler. He barely does damage. I don't think you should nerf the shield portion.
An Undead brat4 votesNot the portion, only the CD. Also his damage is pretty tricky - he does not deal much, unless you are not able to burst him (which you are often not) and get in an extended trade with him. Then he deals quite an amount with Daisy and Brushmaker's passive, which you notice after a period of time, not to mention he'll have Red buff most of the time thanks to the sharing passive, which is another damage source and helps him to kite even more.
Oleandervine1 votesI think this is a good nerf. I do feel like his shield is a bit bonkers, and it's CD seems incredibly low for how much it actually does (Damage, Shield, Slow).
Ionian Vulpix1 votesI feel like he shouldn't be able to use smite on enemy jungle camps before level 3.
MxWhiteKnight1 votesHonestly.
They should make it so Ivern gets 10~20% less exp from camps. He doesn't fight them, so he runs zero, ZERO risk of ever dying in his jungle. And he only gets low on his first 3 marks. Nerfing exp via the item punishes everyone that focus on other items first (Like 1 jg item gives 100% exp on first spawns but for second spawns you need the other one, and for third spawn you need the completed smite option). This seems like too big a nerf in a broad spectrum. But this is just a one off idea really (I mean he's not even fighting them, why should he get full values? That's the whole point of JG).
Also, stealing buffs level 1 shouldn't be a thing. That's just so stupid. Like if he wants to steal it, make enemy buffs have "charm protection" or some crap where his mark can't be instantly smited and has to wait for the full mark. It's stupid getting ganked by ivern 15 seconds into laning phase because he stole the red buff.
As Qt, Scarra and DLift said, buff sharing HAS to go. That shit is stupid because you can always smite secure it and your laner gets a copy. And for his shield, he needs a fixed 10~8 second CD immune to CDR like Yasuo's Q (were only AS lowers it). Because he shouldn't be able to spam a slowing, damaging shield. EIther keep the damage and a fixed CD or take off the damage.
Like, it's so Ironic that a pacifist jungler is the most broken thing in the jungle right now in terms of "supportive, team" junglers. IMO the thing that has to go Asap is buff sharing, level 1 steals and doing something to his E at least a fixed CD, it doing damage and slow is ok, but every 5~4 seconds? Jesus no. Q and W is fine (hiding epic monsters is stupid though, why did they ever let him do that? 0 Mana 
Ult all over again).
SexualizeOatmeal1 votesIvern has a set health he will be at while clearing camps. Gank him early on when his health will be low.
MunchCrunchLunch1 votesremove sharing buffs. thats it
Lugg1 votesI agree that needs to definitely happen, but I also want them to increase the time it takes for him to prep camps. There is zero counterplay right now since he can take your buff for free in a couple seconds with smite at the start of the game.
General Esdeath 1 votesI think instead they should make it so the CD doesn't start ticking down until the shield is gone
SpecterVonBaren1 votesIn return make it so he gets half of his W on hit damage even when not in a bush.
Oelyk1 votesTL:DR. Increase E CD by 2s, all ranks.
An Undead brat1 votesBUT MY WAY TO SAY IT IS PRETTIER!!!
Oelyk1 votesSimplicity is elegance.
morris11 votesThe only problem I have is with his invades. As such, my idea:
Ivern cannot smite groves in the enemy's jungle to instantly free the monsters.
(Compensation) The first grove placed in an enemy jungle takes 25% of the normal time to grow (10 - 1.5 seconds based on rank). This effect has a 180 sec cooldown.