fixed certain boss abilities being broken due to how the invulnerable checks worked

all forms of physical damage are now affected by piercing damage items
buffed all of venge skills
weaver E scaling buffed from 7/6/5/4/3/2/1 to 2/1.5/1/0.7/0.5/0.3/0.2
bosses can no longer instakill through invulnerability (riki tricks of the trades, io ult, jugg omni, etc); bosses no longer do damage when dead (report if i missed one)
other minor changes and fixes

fixed a bug where mobs sometimes gave several stacks of rot damage
rot damage scaling tweaked, 500 at max level (caps at 60k bonus damage max level at the current game end)
rot base damage and radius buffed

rot bonus now only increases for non-summoned units, lowered rot bonuses slightly at later levels, buffed at lower levels

tweaked how the attribute bonus works, now stat gain scales (so instead of the standard static stat/level it increases with levels); bonus from skilling attribute bonus has been reduced; getting maxed attribute bonus roughly doubles stats from dynamic stat gain; so while still worthwhile to get stats they are less strong than before as you get roughly 50% stats for free now ( stop only skilling stats)
pudge rot reworked, now gains bonus damage based on the amount of creeps killed; bonus self damage does not damage pudge.
centaur double edge reworked, now gains bonus damage based on the amount of strength centaur has, bonus damage does not damage centaur
fixed some bugs with skinwalker

Added Az'ual, The Skin Walker. Has 3 forms; every form has a specific function.
In Behemoth Form, Az'ual gains bonus hp (and armor when ult is skilled); gains charge and turmoil. Charge charges him to the point location and deals damage in an aoe around him on arrival.
Turmoil performs a counterattack to every enemy that hits him during the buff duration.
In predatorform, he gains bonus attackspeed (and movespeed when ult is skilled) as well as a chance to apply bleed to the enemy. He gains the abilities lunge and maul; both place bleed stacks on the target; lunge jumps him to the enemy while granting him and allies bonus damage while maul slows the enemy
in normal form, he goes from melee to ranged; has bonus mana regen and has the abilities stellar drops and coruscating bolt; both can be applied to both allies and enemies; healing allies and damaging enemies. When hit by one ability, you will gain a buff that causes the opposite ability to deal more damage/heal more health
The ult will change in mana cost and cooldown depending on the form; in mage form it will root all enemies and deal damage to them over time and heal all allies during the duration.
In predator form he will deal a single critical attack that applies bleed as well as ignore the enemy's armor.
in behemoth form he will stomp around him periodically, disarming and rooting the enemy for a short duration.

added some tweaks to hopefully stop invisible enemies stopping progress; if i get better bug reports about how to replicate it i might be able to fix it for certain

removed killcam, will no longer block amount of lives left.
axe spin now deals bonus damage based on axe's armor
ghost scepter upgrades will now lower the damage gate; meaning lv2 ghost scepter in impossible will lower the damage dealt by rightclicks from bosses from 50% max hp as max damage to 30% max hp as max damage; every upgrade afterwards reduces the damage dealt by -5; maxing out at 15% max hp as the boss damage cap

fixed drow q agi multiplier not scaling well
added particle effects for desolator and skadi upgrades

reworked drow. Frost arrows is now an innate ability; replaced by Bullseye: Shoots an arrow at the target location and damages and disables the passives of all enemies it hits
drow W replaced by Leaping Shots: Drow leaps in the direction of the target point and shoots arrows to all enemies around her; the arrows will silence enemies hit
Drow E now gives damage to both melee and ranged units

changed ng+ damage reduction scaling so mobs don't get too easy too fast