I really like this idea. Items like Quill Coat and Spirit Stone would probably need tweaked a little as they are essentially upgraded machettes, basically bringing down the items to a level more on par with Machette on AD junglers, taking away the 20armor from quillcoat and reducing the bonus damage on Spirit Stone would be necessary. I see a problem with having Quill Coat and Cinderhulk Enchant at the same time as the sapping barbs and immolate passives would be strange to balance around when it comes to Baron and Dragon, but there is a possibility to add a part of the passive to include special interactions with Epic Monsters.
I really like the idea of bringing back Juggernaut and Magus as I thought it was kinda BS that different styles of AP and Tank junglers got screwed in the process. I will say that Runeglaive and Cinderhulk were overall better than both of these old enchants, but some champions really wanted CDR and Tenacity over clearspeed, moderate damage, and lategame tankiness. For instance, Elise was a champion who benefited heavily from the old Juggernaut over Cinderhulk as she wanted immediate stats that could be useful instead of scaling stats that would try and help her weak lategame. Her clearspeed was already among the fastest in the game, so Cinderhulk didn't help her there either, but I think it is still a better option than Runeglaive or Magus. Other champions that would use Juggernaut over Cinderhulk would be strong initiators and more midgame focused tanks/fighters, but some would have to make a choice on whether to get Juggernaut or Cinderhulk based on the situation and what the team needs.
I like the Guardian's Horn passive/active idea as a replacement for Tenacity as it makes you feel like this unstoppable juggernaut chasing down the enemy team. Magus I still think needs a little tweaking as I do think it is too generic. I feel like it would be difficult to make it so Runeglaive and Magus have unique strengths as you can easily see the difference in strengths of Cinderhulk and Juggernaut one being a more initiator focused, or mid-game focused item and the other being more of a power farming tool and lategame hyper tank item. Runeglaive is obviously going to be for spellblade users which are more focused on the early and midgame assassination potential they have, so I see it as pretty fine where it is (though it might be OP right now), but Magus is tricky as the item should be for pure Mages but it shouldn't be just hands down better than Runeglaive for spellblade champions, so giving it a worthwhile passive/active would be hard to do. I REALLY like 20%CDR for Magus as it encourages these Mages to use more and more abilities, but the amount of AP it should give is dependent on how strong the Magus passive would be.
As a little side note, I think Warrior is too generic as well right now; it has had an iteration on the PBE that looked a lot like the old SotEL, but was taken off probably due to it being too strong on certain junglers (*cough 
). I do think that this idea is still solid, but needs tweaking to not just favor the highest base damage junglers.
Basically what I want to ask anyone who reads this rant is what passive/active they would give Magus that would make it strong on the Mage junglers without being hand down better than Runeglaive on everyone (Eve, Diana, Fizz, and Ekko should probably want Runeglaive if they are going AP; judgement call on Nidalee as CDR and more AP benefits her siege power). While writing this I've thought about something that might work. Magus could include a smaller Liandry's style DOT passive (1% instead of 2%). Most of the pure mage junglers have some sort of spammable or DOT ability that would keep the passive on at all times and it would help them with clears as well. The enchant could have 60AP and would be a definite different strength for an AP jungler to have. So in the end, the AP jungler would choose between burst damage in Runeglaive, or consistent damage in Magus which benefits different junglers in different ways.
So my suggestion for a relaunched Magus would go as follows. Magus Enchant: 60AP__ 20%CDR__Unique Passive--Burning Tears: Dealing spell damage applies a damage-over-time effect that deals bonus magic damage equal to 1% of the target's current health per second for 3 seconds. This bonus damage is doubled against monsters and movement-impaired enemy units (capped at 100 damage per second vs. monsters). This could be modified if it is overpowered or underpowered but I think it is particularly strong on champions like Karthus, Fiddles, and Amumu. The Burning Tears passive would have to be added to Liandry's to make sure the passives couldn't stack. Tell me what you think. Peace.
