SPOILERS!!!
How to start? I have walked away from watching Arcane S2 with mixed feelings, and, as someone that thinks S1 is a 9/10, I'm left in a sense of disillusionment.
Let's start with the pros. Firstly, again the art style and direction is top tier, with beautiful imagery and stunning effects. The world of Arcane is filled with magic, despair, war and anguish, but a sense of fighting for a good cause. The theme of this series is all about forgiveness for each other, no matter who you are or what you've done, a person can find redemption if they seek it which is a beautiful thing.
Now the cons. Firstly, there were no action sequences throughout the entire series. They were mainly made up of short clips and still shots that were pieced together. S1 was notable for it's awesome action choreography so I'm astonished at the lack thereof. Secondly, though there were individual story arcs, which on their own were told brilliantly, they never actually come together to form a single conclusion. Lastly, though I mentioned the beautiful theme of forgiveness and redemption as a pro, this is heavily outweighed by the simple fact that every episode has a moment of vulnerability with a character which leads to a terrible consequence/s. The best example of this is Jinx. Many times she was caught in a dilemma but because of the vulnerable people, she was spared, which lead to consequences of more people getting hurt.
I have so much more to say but I just wanted to keep it simple.