Since this will be something so relevant next update, regarding both Cole vs Mc fight and possible evolutions:
1. As i said before this seems a perfect spot for Cole to evolve, not just his evolution has been foreshadowed a lot but also the situation seems to be that he will have to fight alone at least against Mc and Deryl, Michael and Alice can be easily healed by both to join the fight and possibly if Liz/Amber evolve they can join too, so from best to worst situation for Cole he will need to fight alone against two lvl 3 up to four lvl 3 and two lvl 2, not the best odds.
2. If SIN members interfere we need to consider how it could happen, right now i doubt that Shen or Charlie would bother helping Cole, Jared might be close to him but i doubt he would dare or even care to try, Zara seems to like him and Briar is very forgiving so those two are a possibility. Zara has the marks but we don't know how useful her powers are in a fight, Briar however can heal and would whitout a doubt be useful.
3. if i had to guess either Cole will fight alone, be overwhelmed and need to evolve or Zara/Briar will return and try to help in a more supporting role, maybe even be forced on that role because Cole is a bitch and would refuse more direct help as the condescending arrogant asshole he is.
4. Since you guys are bringing up monsterfication that's interesting, i don't think will be the case for Cole but i though about a possibility, what if Cole while losing the fight tries so hard to evolve that he starts to monsterfy and accepts to take a vow from Charlie like Shen did to evolve properly, it would be a good humbling experience for this prick.
5. As for Mc i really do think that it's too soon for him to evolve no matter how the fight happens, he just got acess to the other world and has a lot of development and training on the memory field, i expect at least two more updates and then maybe he evolves at the end of the third, next update will be the end of the twins arc and the following i suppose Ella's return.
I don't see Cole's evolution as foreshadowed, but more as a way of showing us how full of himself he is, because beside is own words nothing proove that he's close, it's more is pride talking. And since then (it was before Valravn fight so a long time already), he still a level 3 weaker or close to mc who is a newborn level 3.
Also, the biggest problem with all the theory implying Cole evolution (mine included), is that he would become too powerfull to be handled by mc alone.
So it would be more likely that either both of them evolve, or none .
Alice and Michael even if healed are no match for Cole, Cole power is compared to Met and the only reason Michael could put a fight with Met was because he could absorb Energy ( and they still are affected by the drug since Michael could only use the little he absorbed on some corps) and Deryl will likely help to evacuate both of them and also Liz and Amber body , and don't forget that a lot of monster are left in Sin base (and whe know of some B and C rank who wont be so easy to handle for them )
For the others kids , it would be difficult since they both have leaved already but since Briar was keeping an eye on Cole and Shen when they where talking, it's possible that he could have asked Hex to bring him back and maybe that he could even heal Amber after seeing what Tanos did to her and also seeing who Cole realy is from is own eyes.
Also, in the mental state mc is, i doubt that he would let anyone inferfering in this fight and if the fight isn't interupted maybe both him and Cole will die since it's only a matter of time for hex's dimension to fall ( their fight could even speeding up the process since Hex is wounded and the dimension is unstable) , and this could be the moment for the Nyx brand to come in handy.
I doubt mc was given one for no reason, and Mc didnt even notice the eartquake once he saw Cole with Liz's head so they will likely fight until the other is dead, but by then it would be too late for mc to escape and would be resurected by Nyx.