Scorched Earth: A Brand New New Brand Passive

There's been a lot of talk about Brand lately. Not many ideas, just talk about how he's not satisfying enough. I have an idea: give him strong affected-area damage instead of just area of effect and DoT. Tanks/fighters have Trundle and Skarner, assassins have Nocturne, marksmen need to solidify their identities, and I think mages should have Brand. This separates him from the other mages who step on his AoE DoT identity ( , ) while also introducing something that's completely unique: Rumble's ult strong area-based damage on a mage. It generates distinctive play which, according to Meddler, "...hits on one of [Riot's] primary goals for this work of making different characters have distinctly different effects on the game." Scorched Earth goes perfectly with his fire-elemental theme; finally, he's actually "Ready to set the world on fire!" Plus it retroactively creates a connection to Renekton and Xerath. Brand's pretty old, he's been many places...

As for how Blaze and Scorched Earth interact, Scorched Earth does not apply Blaze; you can step onto, dance on, or even recall on Scorched Earth with no problem. His Q and ult will leave Scorched Earth along their paths, his W is obvious, and his E will leave streaks toward and in a small area around the secondary targets but not apply it directly to them.

Blaze: Brand's abilities light his targets ablaze upon damaging them, dealing a percentage of their maximum health as magic damage over 4 seconds, capped at 320 against monsters, empowering his abilities against them and applying Scorched Earth to the ground around them for 10 seconds.

Scorched Earth will be either a second passive or a passive on his ult. Not sure about how to implement it though, so I just made 3 ideas:

Scorched Earth 1: Brand's targets take double damage from Blaze and will leave a trail of Scorched Earth behind them (similar to Nocturne's trail).

Some things to keep in mind:

1. I took out the 8% on Blaze, because 16% max hp would be ridiculously OP. Gotta find a balanced number
2. Both passives work on his targets; neither his ult nor his E will apply Scorched Earth to secondary targets.

Scorched Earth 2: Brand's attacks deal bonus damage to targets standing on Scorched Earth.

For your consideration:

1. This is a much simpler passive. Extra damage, got it.
2. I didn't specify what kind of damage. Is this AP scaling? HP scaling? Scaling off damage taken? Is it magic damage or true damage?

Scorched Earth 3: The burning ground applies Grievous Wounds and shreds enemies' armor and magic resist. Enemies will only spread Scorched Earth for 1.5 seconds.

Saved the most boring one for last:

1. For balance's sake, 4 seconds is too long. With lowered defenses, they'll be dead by the time it wears off.
2. Scorched Earth deals no damage on its own.
3. This will probably turn him into a support. That is so not the goal, but...

So tell me what you think! I'm trying to make a change, not make a point, so if you have a better idea I want to hear it!