Do we know what tier Danica's monster is?Like I know it's powerful but like what rank?
At this current moment, no. It's not below B Class though. Since MC was able to form a connection to the 11th via Danica. Gestas is probably 3rd Generation at the highest. Possibly 5th or 6th at the lowest. Danica was also able to reach her 3rd Evolution naturally. Which indicates the Gestas isn't that low. Yeah, it took her 2 years but she wasn't exactly using her power beyond killing humans. In fact, she only had 24 power at Level 2 after two years. If Danica used it to kill monsters more, she probably would've been Level 3 in that two year time period. Especially when she evolved to Level 2 in only a couple of days.
There's also the fact WW hasn't reused its design among the hordes of monsters, as far as I noticed. So we can assume it's somewhat unique and that there's not many of it out there, if any at all. It also specifically sought out Danica at night. Showing that it's pretty intelligent. It likely wasn't a random encounter. It knew she was highly compatible with itself and waited until she was alone.
Using the context of its power and Danica's. I would say the mix is mostly 11th, 7th, and a small amount of 8th. 11th because it mostly tied to destruction in general. 7th because Danica X Marks the Spot can't be detected and she can actually hide it's presence on the target. 8th because her powers are called cross light and her Kryqs look like hardlight. Also the Gestas in particular seemed to teleport or sink into the shadows to reappear in front of Danica when she tried to escape. So that's more that points to 7th, since Valravn and it's Lord can do that.
So yeah. Between B Class and A Class. The way Danica killed the B+ Gorgon in seconds. Even with the possible vast power gap of 100s of power (Gorgon can range from 310 to 620 power). I'm mostly leaning towards Gestas being A Class currently. I'm sure WW will get around to releasing a Monster Card for it or give details in game.