The biggest challenge for completing
Killed It is building up a deck that's consistent enough that you don't tear your eyes out while waiting for the perfect hand.
I took the core ideas of my build from
this blog then adjusted it a little for better consistency.
The deck is a
Northern Realms deck, focused on buffing strong siege units with
Foltest, the Siegemaster and stacking buffs on the ranged units, specifically
Crinfrid Reavers Dragon Hunter.
While you don't need every card, you'll want many that aren't included in the starter deck, so at least getting started on the
Card Collector achievement isn't a bad idea.
On top of the core ideas above, my deck focused on consistency with heavy spy usage, and added the neutral DLC cards
Gaunter O'Dimm and
Gaunter O'Dimm: Darkness for an easy way bonus 24-28 strength.
The deck I used was:
Faction: Northern Realms
Leader: Foltest, The Seigemaster
Close Combat:
1x Prince Stennis
1x Sigismund Dijkstra
Ranged:
3x Gaunter O'Dimm: Darkness
1x Dethmold
3x Crinfrid Reavers Dragon Hunter
Siege:
1x Gaunter O'Dimm
2x Catapult
2x Trebuchet
2x Ballista
1x Siege Tower
1x Dun Banner Medic
1x Thaler
Hero:
1x Geralt of Rivia
1x Cirilla Fiona Elen Riannon
1x Mysterious Elf
1x Vernon Roche
Weather:
2x Clear Weather
Special:
1x Decoy
2x Commander's Horn
Hero cards don't really matter much to this deck.
Mysterious Elf is very strongly recommended, because spies are essential to consistency here; everything else is just padding the deck to hit the required Unit Card minimum — that said,
Geralt and Ciri are very helpful; +15 with weather immunity means after round 1 spy setup is done, you can still possibly win the round with a single card for the NR faction card draw bonus.
Besides Spies and Heroes,
avoid regular Close Combat units. For the winning round, you're going to have both the Ranged and Siege rows buffed, so even a 4-strength Ranged/Siege unit is better than any Close Combat unit available for NR decks. Additionally, since
you're not trying to win the match, cards like Villentretenmerth are pointless.
The ideal opponent is another Northern Realms player. Especially the early game players, they normally rarely use weather cards (or only have one in their hand, so you can cancel with Clear Weather) and don't use Scorch. NR players also generally use quite a few spies themselves, so you can use Decoy to turn their spy into yours.
Remember: You don't need to win the game for this achievement, just the round so your goal is to amass as many cards as possible and spam them out in one round.
Ideally, your hand for the winning round contains at least:
1x Gaunter O'Dimm (or 1x Gaunter O'Dimm: Darkness)
3x Crinfrid Reavers Dragon Hunter
1x Commander's Horn
6x any 6+ base strength Siege cards
1+ any other (non-spy) unit cards.
Exact counts can vary a little based on what Siege cards you have — the 3x GOD:D + 3x CRDH Ranged row provides 114 strength after Commander's Horn procs, so you have wiggle room to fill in the last 73 strength you need. For example, 2x
Catapult gives you +64 strength by themselves (after using Foltest's ability), so in that case, you'd only need 2 Catapults and either 1 more (5+ strength) Siege unit or a (10+ strength) Hero. For consistency's sake though, it's generally easier to just stack your hand with a bunch of Siege units than it is to try and get both Catapults into your hand.