I find that the best assaults for Kraken would be Renegabe or Lennox,
Renegabe can just rain dots on Kraken. It doesn’t matter if the shotgun doesn’t hit fully, just one pellet and full dots comes to him. He is also strong at the post dome chase so be sure to punish Kraken hard for that. The downside is Rabe for me is pretty meh against other monsters. You need a damn good team comp with little to no half brained players to ensure that you do well against the other monsters.
Lennox is a safer pick. He autocannon deals wonders against Kraken. Other players think Lennox is weak against Kraken but its the opposite. Autocannon is enough for damage while the squid is in the air. If the squid lands or you caught it trying to evolve a single 3 and a couple of 1’s is enough to tear its armor off.
There are probably other assaults that can work but I only have experience with these 2 against Kraken. Playing as Kraken though I can confirm that Pranell is a pain in the ass to deal with.
---------------------------- Non Assault Counter ------------------------------
Another good way to counter Kraken is if your team has a hunter with an smg/assault rifle as a weapon like Griffin, Maggie, Hank etc. What that hunter will be focusing on is destroying mines. Destroying mines will be a major hit on Kraken’s damage and he wont be able to down anyone since Snowballs can easily be healed and Vortex/LS wont be enough to actually kill anyone. Problem is if you can actually talk anyone in pugs to shoot mines. Every time I play against Kraken I’m the only one who bothers shooting the damned things even if I’m assault. Problem is, who will shoot the squid?