Anywhere but Gold Lane I guess?
Remember the old damage reduction bonus from Old Odette's ULT? I think they should give that effect to Obsidia's because as an MM, her ult is a massive close-engage skill. The linked enemy can just drag her around too with it if they got enough movement speed, making her even more prone to danger. That's why it's not very advisable to use her ULT during clashes, she's just gonna be caught in crossfires.
Another thing to amp up her ULT. Upon hitting an enemy with ULT, her 2nd skill AT LEAST should be refreshed when its on cooldown. I'm using her recently and FR it's super awkward when this happens because her ULT effect lasts only for 3s:
Get near to enemy using Skill 2 > cast and hit with ULT > enemy flails around dragging her > can't adjust position cuz Skill 2 is on 3s cooldown > ULT effect wears off > get dropped on very vulnerable area > die
Like, seriously with this ULT adjustment they can give her a chance to escape a 3 man gank on Gold Lane by:
Run with Skill 2 > cast and hit approaching enemy with ULT > readjust position with refreshed skill 2 (like a Mathilda) > detach from the link > Use Skill 2 to run.
Her early game kit also looks very viable for a roaming marksman. Tried it several times already.
Her stacks are extremely easy to collect with the availability of enemy heroes to constantly hit with Skill 1
Skill 2 allows her to rotate more freely and quickly around the map
She can spearhead ganks like a damage roam with her ULT to ambush and lock down enemy from escaping.
Very noticeable cons are of course: she's squishy; she'll be the one that needs to be protected instead of her teammates; and she doesn't have any CC skill pre-first turtle fight
For me? Actually her kit kinda offers a new off-meta plays that would fit a 5-man or trio team comp matches that utilizes niche strats. With that, devs should make her more viable on roaming, like how they did with Helcurt (from pure jungler back then, now can effectively roam), and make the matches non-monotonous when it comes to team strategies.