I am open about not being a great deck builder, but this was a dramatically bad one.
Step one in making a bad deck for an event:
Rush putting it together, as if hungry wolves were only three steps behind you, about to devour you if you don't get on with it.
Step two:
Make numerous bad decions, and certainly do not pause for a moment to think about how well the units, spells and attachments will synchronise - the wolves are getting closer! Such as: Have numerous flyers in your deck? Add 3+ 1-0 weapons that give flying. This will help to increase the chance of having nigh on useless cards in your hand.
Don't notice that your relic weapon has only one attack, limiting its use. Put 3 copies in. (The wolves are now laughing).
Step three:
Do not test it out in casual or ranked first. Just go straight in, pay your precious gold, and face your fate!
An example of how rushed decisions affect the final deck is that by putting in 4 Elder's Feathers and 3 Signal Flags, I had 7 pretty unusable cards, and lessened my chance of drawing the much better weapons. I also could really have done with a Valkyrie Enforcer when an opponent played Sandstorm Titan! But copies were buried under those Feathers. Result: 0-3.
The wolves caught me, by the way.