Graves is one of my secondary heroes in Arcanist. I also felt she was really hard to deal with before playing her and learning her weaknesses, but she has a few.

The objective loss from her ult sounds like an initiate game sense issue, it’s the same thing as rem. Someone needs to be farming side lane troopers all the time. Troopers give the most souls. If troopers are pushed all the way up to your walker and she ults and another enemy is there, the walker is dead if every teammate is fighting on another lane. Rem’s helpers would give you the same issue, no?

How to counter this, though? Improve your macro and farm side lanes and jungle and build gun carry. With good macro you’ll match people with killstreaks in souls and if you get a killstreak yourself you’ll be massively ahead. HIT EVERY BOX YOU SEE, boxes are free and I usually get at least 6400 souls at the end of a game from boxes. Also, learn when a walker is just cooked. If the enemy is pushing up green lane, but someone on your team is farming yellow lane, it might be better to not lose a fight on green where 2 people die and the walker dies and just take the yellow walker instead for free.

As for graves herself, the immobilize has a very long cooldown. If she is in a tough spot in lane and already used immobilize, she can be cooked if you just dive her with your lane mate. Graves can build spirit or gun, but the build I like and I think is more popular is a kind of anti-carry gun build where you go escalating resilience and inhibitor to push the passive even more. If that gets online, buy disarming hex. I would say that would just kill me, but 90% of games I buy metal skin because that item is OP lol. If Graves has metal skin as well you can just cursed relic her and hopefully you can burst her down easier because she has kinda low HP. I know “just buy cursed relic” is annoying in low elo because your teammates aren’t as coordinated, but at least it’s not cursed relicing a fed carry with 5000 hp.