So I saw the new jungler item for tanks and wanted to try it out on Zac (for the maximum HP of 8k).
When I bought it I thought about combining it with Sunfire to see how they interact. I saw that the aura passives had the same name and were unique but I bought it anyways. What happened next was rather weird. The damage I dealt startet out with the Sunfire damage (36 at that time) and then ramped up at about 7 or 8 stacks of Cinderhulk, while still increasing up to the 10 stacks limit. Sometimes it would deal unusual amounts of damage acting like a "critical hit" (It was about 122 magic damage at that point, there was no critical hit animation but always roughly 200% of the usual damage) and then stay at the base damage. I tested it later without Sunfire but nothing alike would happen. When I bought Sunfire again at level 18 it would do the same thing (roughly 132 magic damage if I remember correctly).
This was tried against minions, champions and neutral monsters with similar results (altered by magic resistance).
I tried recording it but somehow nothing happened. I might try again though.
I am the Element Flaemis
Edit: I made a recording of it and I hope that this will work out :D, the recording lagged a little ^^'