Just got smashed with a 1x yellow 2x red 2x blue team. (Delilah, Zimitka, GM, Arthur and Magni)
I had Santa nearly down when mother nort started…
I got Miracle roll, fire stones, titan attack and green potions.
I think i might consider using 4 reds to get rid of Mother North? Any advice on colours and materials?
I am not that far but I would normally try and bring snipers to the party.
I usually hit them with items first and then unleash my specials.
I heard it was difficult but I’m not that far along yet; I haven’t tried.
I normally color stack for the mob levels (in this case, lots of green against blues), and red against the front bosses. Blues not so much, tho Magni and Arthur are good heroes.
Instead of green potions, I’d bring purple banners to reverse both status effects from buddy and Santa.
And since mother north revives, I’d snipe her instead of the other two.
Also consider bringing mana pots, tornados, and/or timestops.
I’ve found that Zimkitha to cleanse/add attack and Victor to siphon off health/add defense has been really, REALLY helpful. I also use Drake to blind. In this scenario, MN is the problem because she resurrects, so stack another Red like Marjana/Azlar and a healer and you should be good.
Thinking about items? Tornadoes, dragon bombs and time stops. If you don’t have ZimKitty, antidotes.
Use Merlin, he can won for you 
Here is my video of me taking on level 24 advanced stage. Take out mother north and the other two are relatively easy to take down. Notice my use of the dragon bombs and tornadoes. If you have a Victor and Zimkitha, I highly recommend taking them because you’ll notice Mother North gets her special off while she’s bitten. Yeah, Victor stole nearly 1000 hp if I’m not mistaken. 2018 Christmas Event: Stage 24 advanced
Maybe i should have switched Merling for Panther.
I used 4 timestops, 5 big flasks of manna, 5 rock bombs, 4 dragon bombs.
I did succeed in pushing away MN. Then i just missed the one timestop and dragon attack. So it cost me 75 gems to finish easily.