Leader: Harald the Cripple
3x Savage Bear
2x Raging Berserker
3x Berserker Marauder
1x Geralt: Igni
3x Priestess of Freya
3x First Light
1x Donar an Hindar
1x Birna Bran
Savage Bears hurt everything that comes into play. This will trigger your Raging Berserkers. (It will also outright kill your priestesses in round 1)
Raging Berserkers are relatively weak but their bear form is immune to frost which can come in handy. (Frost will also trigger their transformation)
The Berserker Marauders are the powerhouse of this deck. They transform when they hit the graveyard (which makes them good discard fodder) and gain a +2 for every damaged creature on both(!) sides of the board when they enter play. It's not uncommon to see a 20+ str Bear in round 3.
Ciri is for card advantage and if you want you can use her as discard fodder after you've lost a round. You get this card for free when you reach lvl18
Geralt:Igni is her as a safer version of Scorch. It's one of the few legendaries in this deck but it's a very versatile card. If you don't have it, you can replace him with any other Gold. Coral, Yennefer or Zoltan: Animal Tamer might fit this deck well
The priestesses, Sigrdrifa and Restore are obviously for rezzing. All are standard for pretty much every Skellige Deck. Restore can bring back Sigrdrifa and Sigrdrifa can bring back a priestess. (Don't play them in round 1 if you have a Savage Bear in play)
Ocvist is another legendary. His usefulness is limited in decks that don't have rez options so feel free to swap him for the cheaper Uldaryk which also gives you card advantage. Ocvist's ability to damage opposing units fits this deck very well though.
Svanrige and Ermion let you fill your graveyard while drawing replacement cards. (Both are standard for most Skellige decks) Berserker Marauders are your prime choice as discards.
Decoy is the third and last legendary in this deck. You get it for free when you reach lvl20 and it fits in pretty much every deck.
First Light helps you get rid of pesky weather effects. If your opponent isn't using any, you can use them to thin out your deck. (Keep 1 in reserve in case they have Aeromancy)
Madroeme is here because there's always an annoying card you don't want your opponent to rez. Or use it on your Ocvist to keep him alive just a little longer.
Donar an Hindar and Birna Bran are 2 more cards that give you card advantage. They also help you fill your graveyard but you have less control over it.
An early version had Warcry but I found it to be of little use. Maybe if I could find room for Clan an Craite warriors but Harold fits the deck just so much better than Crach an Craite as Leader.
It's important to gain card advantage so you can drop some strongly buffed Bears after your opponent passes.
10 commons, 6 rares, 7 epics and 3 legendaries (most of the expensive ones are either free or staple cards)
Feel free to try it out and above all, have fun with it!