Hi
There are several skills to which I would propose some kind of change and would like to hear what others think. I'll just randomly list them,there is no particular order.
Kraken shell
Rescale threshold for buff removal from 600/550/500/450 to a constant of 450 at all levels.
Reason for this change is if you pick this skill with hero that has starting STR below 20 it will result in your death before buff removal even triggers, therefore leveling this skill in the beginning is partially pointless.
Beside this you can also add spell damage reduction. So it will remove either physical or magical damage and removing 40 magic damage at lvl 4 is really not a big deal and will only increase chances of picking this skill.
Blur
As much as I remember it was already request to be nerfed. Personally I don't find it OP but sometimes it is strong. So we can rescale it in one of these two ways:
lvl1 - 20%, lvl2 - 28%, lvl3 - 36%, lvl4 - 44%
or
lvl1 - 26%, lvl2 - 32%, lvl3 - 38%, lvl4 - 44%
Desolate for melee, ranged, and illusions
Currently desolate makes a difference if you are thinking between melee or ranged hero. For illusions that doesn't count because on melee or ranged illusion desolate will deal same amount of damage therefore favoring ranged heroes. So, if it is codeable, please set those damage values something like this.
Melee hero: lvl1 - 20, lvl2 - 40, lvl3 - 60, lvl4 - 80
Ranged hero: lvl1 - 12, lvl2 - 24, lvl3 - 36, lvl4 - 48
Melee illusion: lvl1 - 10, lvl2 - 20, lvl3 - 30, lvl4 - 40
Ranged illusion: lvl1 - 7, lvl2 - 14, lvl3 - 21, lvl4 - 28
Mana break
Bring back this skill to illusions and code it like desolate:
Melee hero: lvl1 - 28, lvl2 - 40, lvl3 - 52, lvl4 - 64
Ranged hero: lvl1 - 16, lvl2 - 24, lvl3 - 32, lvl4 - 40
Melee illusion: lvl1 - 14, lvl2 - 20, lvl3 - 26, lvl4 - 32
Ranged illusion: lvl1 - 8, lvl2 - 12, lvl3 - 16, lvl4 - 20
If this values seem still too much nerf them like you wish.
But IMO you could leave this values and nerf the damage that is done after mana burn from 0.6 to 0.5 or even less. Nerfing this value will make illusion builds being less IMBA.
Null field
Personally I have never seen anyone picking this skill which doesn't mean that it's not picked but I assume that it is very rarely. In my opinion I would buff it a little
lvl1 - 10%, lvl2 - 15%, lvl3 - 20%, lvl4 - 25%,
and make it clickable. When clicked it's AOE will change from 900 to global and if activated on time it could save someone from mc+wrath or something similar.
Set CD to something like 100 sec (or what ever you think is appropriate) and duration of global effect to 4 - 6 secs.
Degen aura & Natural order
Increase their AOE to 400. No special reason for this besides making them a bit more effective. Doing this wont make them even near to OP so why not.
Flesh heap
Increase it's AOE to 600 to match the range of most ranged heroes since we can pick it on them. Lots of time when you don't make last hit in team fight you are left out of STR bonus because you were not close enough. Glaives of wisdom have 900 AOE so increasing AOE would be at least fair change.
Frost armor
Very weak skill and a pure waste of skill slot. Obvious suggestion is to buff it and make it worth picking:
lvl1 - 4 armor, MS reduction 15%, AS reduction 35%, 3HP regen
lvl2 - 6 armor, MS reduction 20%, AS reduction 45%, 3HP regen
lvl3 - 8 armor, MS reduction 25%, AS reduction 55%, 3HP regen
lvl4 - 10 armor, MS reduction 30%, AS reduction 65%, 3HP regen
Slow effect should effect both melee and ranged attacker.
3HP regen was added because this skill can be casted on structures as well so it would be nice addition besides living armor for healing towers.
Since the buff is huge I would also suggest to increase mana cost of spell, reduce duration to 30 sec, and increase CD to something between 6 - 10 sec.
Chain Frost
Speed of this ulti projectile always bothered me. I would trade infinite bounces for speed buff of about 25% or 30%. Having infinite number of jumps is pointless because eventually everybody will die or scatter around and end the ultimate. It's a win if you kill everybody but I rarely see that. It would be much more useful if you increase the speed of projectile a little so that it can deal more damage before heroes scatter.
lvl1 - same damage, (30% faster), 10(15) jumps
lvl2 - same damage, (30% faster), 10(20) jumps
lvl3 - same damage, (30% faster), 10(25) jumps
Scepter upgrade represent values in parenthesis.
Freezing field
I find this ultimate really strong. Amount of damage it can deal for its duration for only 250 mana every 70 sec is just too much.
Double the mana cost or set it like it's in Dota 200/400/600 and increase CD by 10 or 20 sec.
Beside this I would also remove 2 secs of repel and replace it with linken like Death ward has it.
Hero Terrorblade
Remove the footprints when hero walks. No reason for them, they just reveal your path and you can easily be followed.
As much as I remember some other hero leave footprints as well but cannot recall which one, maybe Tiny?
Item Diffusal blade
Replace charges with CD.
lvl1 - 40 sec CD
lvl2 - 25 sec CD
Mana burn:
Melee hero: lvl1 - 20, lvl2 - 36
Ranged hero: lvl1 - 12, lvl2 - 22
Melee illusion: lvl1 - 10, lvl2 - 18
Ranged illusion: lvl1 - 6, lvl2 - 11
That is all for now, regards.
P.S.
I forgot two spells.
Dragon blood
Nothing big but I would increase HP regen from 2/3/4/5 to 2/4/6/8.
Reactive armor
Increase the armor and HP regen gain per hit from 1 to 2. Keep the stack limit of 4/8/12/16.