Pixelmon Mod

Sneasel.

1.) It used to be a Pixelmon starter.
2.) In spite of spawning in the Birch Forests, the region with Professor Birch was the only region (before OR/AS) you couldn't obtain this Pokemon in.
3.) This Pokemon all had a Friend Area basically for itself in Mystery Dungeon Red/Blue Rescue Team.

That's pretty easy, it's Eevee~

Hints
#1 It's lives deep in the ocean
#2 It can evolve into two different pokemon
#3 A certain item makes it hit like a truck

Clamperl, right?

Hints
#1: This pokemon is a dual-type.
#2: They are said to ride the winds.
#3: this pokemon has horns.

is it gligar?

It was once hailed as the only pokemon without weakness
It can mega evolve
It consumes crystals

sableye

1. before gen VI it was a single typed pokemon
2. On smogon it viewed as is NU unless it has a certain item
3. It's from gen III

It's Mawile with a Mawilite

Hints
#1 Normal Mc. Normal Pants.
#2 It's shiny form is a complete waste of possibility.
#3 It's a pretty devastating opponent in a spin-off game.

is it shedinja? (spin off being pokemon mystery dungeon)

1. it's a gen 6 pokemon
2. it's electric and normal
3. it's ability contradicts it's dex entry

[quote="AuraWalker"]is it shedinja? (spin off being pokemon mystery dungeon)

You were right with the spin off, but I ment Kecleon with that. I still wish that the shiny form is like the spin off instead of normal color with blue stripes.

Back to topic: Helioptile with dry skin.

1st: It's a psychic type.
2nd: It doesn't appear as wild pokemon anymore.
3rd: From a certain day on will it always evolve despite holding an Everstone or Pressing B.

Looking back at that last one after Sun and Moon were released, it makes even less sense. "It doesn't appear as a wild Pokemon?" "It will always evolve, in spite of holding an everstone or pressing B?"
That implies it evolves via evolutionary stone. That way of thinking narrows it down to Exeggcutor, Starmie, Gallade, or Musharna. But, the phrasing also implies it's the pre-evolution, which means Starmie doesn't count, and the other 3 are easily obtainable in Gen VI.
I can only guess it's Musharna, since they appear in the wild in Unova.

1st: Like the last post, this Pokemon can really drag on.
2nd: It loves the sun so much that people of a certain region say they know the true form of this Pokemon.
3rd: It took an old species and turned it into one of the big memetic Pokemon.