Overview
Obsidia is a marksman who is reliant on her passive in which will be the main power spike and damage for her. In terms of farming in the early game try to maximize her 1st skill on the wave, you can freeze your lane to spam her 1st skill on the wave to fully maximize stacking, avoid dying and continue farming until you reach your 3rd main item which is more or likely her power spike.
Strengths
Obsidia's power spike is when she is fully stacked on her passive so to maximize the stacking you need to avoid unnecesarry fights and continue farming until you have the right items.
Weaknesses
The weakness of obsidia is the lack of damage in early to mid game since she is a marksman but she can be very useful in cancelling assasin heroes dashes so use them wisely.
Attack speed
Trinity item for tanky comps partner this with 1st emblem set
Crit build
Most used build and this is partnered up with the 2nd emblem set
Tanky enemy comp
Assasin emblem because of penetration and movement speed which she will use to tear the enemy's health then for the 1st talent you can joggle from fatal or adaptive pen (only if their comp is tanky) second talent is bargain hunter so you can buy your items faster or you can go with weapon master for extra damage then lastly is the 3rd talent you can use quantum charge since you are gonna tank some waves because of freezing so you can heal a bit of health and is also really good in kiting, you can also use warcry for more damage.
Normal enemy comp
Assasin emblem because of penetration and movement speed which she will use to tear the enemy's health then for the 1st talent you can joggle from fatal or adaptive pen (only if their comp is tanky) second talent is bargain hunter so you can buy your items faster or you can go with weapon master for extra damage then lastly is the 3rd talent you can use quantum charge since you are gonna tank some waves because of freezing so you can heal a bit of health and is also really good in kiting, you can also use warcry for more damage.
Battle Spell
Flicker since she doesn't dash she basically just moves fast
Mid game to Late game
For the early game you should avoid taking fights and continue stacking your passive, freeze lane as much as possible to maximize using the 1st skill and stacking, avoid dying and continue farming until you make it to the mid game in which you can help your team pick off someone who has a lot of dash and ult him/her to cancel the dashes, once you are fully stacked you can confidently kill frontliners with ease and save your ult when most of the damage dealers are distracted so you wont die while using your ult. Free hit as much as possible if you are getting zoned just angle yourself for your ult and hit the backline if your assasin is already at the backline (only do it if your assasin goes to the backline if not then dont do it)
Best With Minotaur
Mino heals and has good aoe just stay behind mino and you can confidenty free hit no matter what hero they have and stay within his ult to make sure his oasis helps you in dire situations. And make sure you ult the right person.
Watch Out For Belerick
Belericks passive hurts so much for Obsidia since her passive is like an infinite passive for belerick so i think avoid trying to attack belerick as much as possible