Well I know a lot about Flamvell, and a little about Nordics, although I haven't tried them together. Even though I haven't tried them together, I know how each engine runs so I should be able to help you significantly. First, Shaman is crap. Plain and simple. There's no reason to run him. Poun is okay in some builds but is uneeded in this one. Your basic Flamvell engine is:
Firedog x3
Magician x3
Rekindling x3
And maybe a teched Hedgehog. Valkyrie I don't like at all either. She isn't quite crap like Shaman, but...there are many things that work better than her to summon the gods. Plus the rfging doesn't help the engine. Your basic Nordic engine is:
Horse guy x3
Black goat x3
White goat x2
Vanadis
Super special awesome hamster x3
Fetters x3
Ryko is good for both flamvells and nordics, plus he's an absolute becissity for getting rid of Oppression when you have a set Hamster. So 2 of him should work. Gravekeeper engine isn't needed really so drop it. Some spells and traps aren't needed either so it should look roughly like this I suppose:
Monsters: (20)
Horse x3
Black goat x3
White goat x2
Vanadis
Hamster x3
Ryko x2
Firedog x3
Magician x3
Spells: (10)
Reborn
Hole
Trunade
Mst x2
Rekindling x2
Duality x2
Avarice
Traps: (10)
Mirror
Torrential
Judgement
Warning x2
Prison/bth x2
Fetters x3
Extra:
Odin
Thor
Trishula
Stardust
Scrap dragon
Colossal
Red dragon
Blackrose x2
Ancient sacred wyvern
Scrap archfiend
Ancient fairy
Brionac
Gaia knight
Catastor
Keep in mind, even though I know a lot about both, I haven't tested Flamvell Nordics so idk how well this would actually work. Also it's subject to change some cards, but this'll give you a rough idea. A VERY rough idea, seriously I just took the engines and threw the deck together in 2 seconds And give normal Nordic another try, they're pretty good