Overview
My playstyle for obsidia is don't over extend be patient you just need to last hit the minions to get a lot of gold in the early game but always remember to check always the map because some of the enemy will gank at you.
Strengths
Her hero strength is the heroes that doesn't have so many dash or squishy heroes example of many dash heroes is Lancelot it will be a 50/50 chance that you can hit Lancelot with Obsidia's ultimate.
Weaknesses
Her hero weaknesses are heroes like Karrie, Alucard, Belerick, Karina but not only hero can counter obsidia you can counter obsidia by just buying Blade Armor or you use vengeance because it will be a lot of return damage to obsidia because of her passive skill.
For squishy and tanky heroes
When it hits late game i sell the boots and change it depends on the enemy, when the enemy are tanky i change it to Sea Halberd but if the enemy is Physical Damage or all Damage dealer i change it to Wind of Nature
Attack speed and fast item
I use war cry because of Obsidia's passive once you reach the max stack of Obsidia's passive which is 25 stacks you will easily use the Emblem War cry you'll know if you will read or understand the War Cry emblem
Battle Spell
I use flicker for Obsidia because she doesn't have enough mobility but sometimes i use vengeance when the enemy picks Karrie you'll know why when you encounter Karrie using vengeance
Late game Obsidia
You just simply be patient in the early game and don't over extend just last hit the minions and don't worry for the enemy taking the crab because last patch the crab was nerfed and it now give low gold so you don't have to compete with the enemy taking the crab you can take it when you know it's safe and if you already build all your 3 core item you can go with your teammates on teamfights and remember when it's on the second turtle you always need to be there.
Best With Angela
Obsidia with Angela is just so OP
Watch Out For Karrie
Karrie is the only one who can counter Obsidia, Karrie with vengeance is really the counter for obsidia