Monster, Bosses and Higher Difficulties

I know I know GGG is working hard on Act3 right now, but this is a suggestion for the future in general.

It's mostly about Monster Abilities, Boss Fights and how they should become harder in later difficulties.

Let's begin with some Monsters I think are lacking in difficulty especially in the late game.

I'll add more Monsters later to this list right now I'll just focus on one particular type of Monster:

The Zombie.
The zombie is okay in normal. It's slow, dies quick enough and gives a good amount of EXP.
Perfect for every new character or new player to slay.
Even the blue or yellow ones aren't that dangerous.

But as soon as you beat Normal fighting them again becomes a joke.
By that point you have a good number of awesome skills and good gear, while zombies only have more health and deal more damage (if they hit you that is).

My suggestions:

Give them more abilities on death or while alive. I actually have to say that I feel there could be more abilities on certain circumstances, let's just look at Diablo 2 for a moment.

Ice enchanted, Fire enchanted and Lightning enchanted.
We all know them from d2 attack them and you get shocked by lightning bolts, kill them and they explode either in a firey explosion or frosty nova.

We already have "Tar-Zombies" which are fine, but not a real thread, more like an annoyance.

To make Zombies more fearful enemies on later difficulties consider this:

Give Zombies abilities on death. Like exploding on death for rares or magical ones.
Or what I've been thinking about, when they die they release toxic gas (aka Poison arrow green cloud), this way you have to think where to go after you kill on, and if you face more than one you need to hurry up or have some sort of ranged ability.

Mods on blue and yellow zombies should have a smaller pool with more effective abilities, like faster moving and attacking + frenzy + haste auras. Facing fast zombies is really frightening, because you know they hit hard and take a good punch but are mostly slow.

I'm sorry for this suggestion but I think it's a good ability. Diablo 3 has some zombies that move on the ground after you kill them.
PoE has these little annoying crabs (see my avatar) they also survive their first "death", why not make some special zombies that work similar.

While we add it, why not give some Necromancers the ability to make zombies into Suicide bombers, that mechanic works quite well and if you couple it with the poison cloud you get some serious cool fights and mechanics!

Moving on to Bosses:

Bosses work quite well in Normal, but for the later difficulties I'd like to have a bigger challenge. Just boosting up their Life and Damage and maybe give them some resist won't cut it.
Fighting mechanics is more fun than fighting numbers.

Let's start with Hillock.
Hillock is fine in normal, you don't want to face the hardest boss ever before you reach the first encampment.
But on ruthless/cruel whatever it will be if we have act3 he is not that frightening.

Here my suggestions:
Normal = stays how he is
Dif. 2 = give him a "shieldcharge" ability. That's it, that alone makes him a much more interesting fight.
Merciless = Additional to the Charge, I thought about 2 other things:

First: Enragement = after lowering down to 50% health, he gains 10-20% movementspeed, attackspeed and regenerates life.
Second: "whirlewind" like attack, he screams pulls his sword and starts spinning a few seconds, if he hits you, you take massive damage, he is invincible as long as he does it, so ranged classes don't have an advantage while he does it.
There is just enough time to escape but his radius should be very wide so you actually have to run away. After he finished he is dizzy for a short while leaving him an easy target for your attacks.

Brutus:
Works fine as he is: I'd suggest also to give him some sort of enrage mode at a certain lifepool level.
But what I'd like to see is some environmental stuff going on.
My suggestion:

The pillars in his dungeons are now like "flame totems" they sometimes release a breath of fire. Moving through it burns you and deals a huge load of damage, so you have to think about where to go when you run away from him... and you should run away sometimes!

Faregraves:
He is okay-ish on normal but could be a bit more exciting.
Suggestions:

Normal: Instead of making him a normal Skeleton make him a bit "Lich" like and let him float instead of move on his feet, this way he would be faster and had more moveability, besides that give him a "spectral fist" attack. What I mean with that is some sort of ghostly ranged melee attack that deals physical damage, this way he could deal with casters and rangers. It would be a bit like a lightning strike just that it doesn't fork out, nor is it lightning and looks more ghostlike.

Dif 2: He has very low health, but if you kill him he turns red and summons fire Skeletons, besides his Ghost ranged attack he also has the flametotem firebreath.

Merciless: Same as Dif 2, but he actually splits into 2 "Lichs" one blue-ish one red-ish, they may take turns attacking you, one with a firebreath that leaves burned patches like Vaal oversoul just with fire, and the other one has a firebreath that is blue and is actually Ice, and leaves the Icepatches that Vaal also does.
Both summon skeletons Fire damage ones and ice damage ones.

Merveil:
Normal = should stay like it is
Dif 2 = Her first version gets a "cleave" attack that has a blue effect instead of the orange one that we use, besides that it should have a damage bonus instead of dealing 90% the damage. It's ranged should be a bit more than a normal sword attack of hers. She uses it when she is close to you and you try to run away. Of course it should freeze you if you don't have enough cold resist.

Merciless = Her second form casts a Fog that slows you and deals Ice damage over time. Not much but just as much that some characters know now they have to hurry up or it's over.
Maybe second form wouldn't have as much life as it has now so you can kill her faster.
Besides that, sometimes if you hit her she shatters like frozen enemies you kill, and respawns somewhere else and fires an Ice Spear or Frostbreath at you.
She also summons spawns at intervals, if you kill the spawn they explode like freezemines + damage. Maybe give it a delay so melee classes don't have a disadvantage and can escape but give it a wide radius.

Act 2 is fine right now, but maybe I'll add some ideas later here.

That's it.

And keep in mind, these are just general suggestions for the future of PoE and making the game harder in later difficulties.
All skills I've described of course can be replaced by anything GGG feels appropriate, but I hope this will be considered!

Thank you for your attention.

I'll rework the text later again, but for now I'll go sleep.