As a Chronos fan, I really wish they brought back Gem of Binding. Removing that item was a huge nerf to him. He's still good, but nowhere near as deadly as he used to be.
Also, what are your favorite assassins to use in Arena? I almost never seem to do very well with them. The combination of being melee and squishy does not go well when the enemies are constantly bunched up. But I see plenty of people absolutely wreck with assassins, so I'm starting to think I just suck.
Kali is the only one I can consistently do OK with. She has a stun and her ult + passive combo lets you go balls to the walls and get away with it.
I like Hun Batz for Arena because he has the best teamfight ult of all the assassins. However, I usually play with randoms so the backup is often not there even when I use emotes and execute a perfect blink + ult into the middle of the enemy team, I end up dying because my teammates were too slow to follow up. So that's discouraging.
I just can't get the hang of Loki, and I've been playing him for a long time now. I go up against some amazing Loki players and I still don't understand how they do it. I spend the whole match looking for squishy or low HP enemies to separate from their team, and then I pounce and their teammates catch up and kill me. But the good Lokis can somehow avoid this fate.
Bastet is pretty cool. Honestly I kinda forgot about her until I made this post. I stopped playing her for a long time because when she was OP everyone picked her and I got tired of her. I'm gonna try playing her again.
I used to like using Arachne purely because her ult was hilarious and extremely satisfying to land, but now it's gone. I don't really like the new Arachne so far. She's an autoattack machine but that means that I run into the same usual assassin problem I have to get close to attack and I end up getting CC/burst down by ranged gods. The same thing goes for Bakasura and Ne Zha.
As for the rest, let's see: I see Mercury a lot but I don't have much experience with him. The few times I played him I didn't do very well, but I was probably building him wrong. Serqet seems pretty cool, I'm interested in her. I hear her 1 is bugged right now though. I am absolutely terrible with Thanatos. I just don't like him. I'm still not used to Thor being classified as an assassin, but anyway I never owned him. He has that great stun and escape, so maybe I should try him out some more. And finally there's Fenrir. I almost never play him but when I did I felt like he fell off like crazy.