Reskin the swift strike buckler like twenty times and stick that in a prize box.
Everyone uses and loves it, it doesn't cost radiant fire crystals to attain and use, it applies to all knights rather than just endgame players and the original swift strike buckler is ugly as sin on most costumes. Need I say more? Because I'm going to.
What it's gonna look like
It could look like just about anything cool and I have a ton of ideas for this-
Common: Recoloured swiftstrikes, military, divine, prismatic, heavy, maybe even add some new flavors that are just other colours.
Uncommon: Reskinned breaker shields with new emblems, and just the breaker shield model. "Modified to behave like swiftstrike".
Rare: Breaker/swiftstrike shields with effects, like the voltaic suit/celestial sabre. Just the hexagons, or something similar.
The 1%: An entirely new model or interesting image, maybe a different looking shield bracelet or a gear halo.
If you want something prize box related that'll sell like hotcakes and make players love you, well here it is.
EDIT: Meep had a good idea for this as well- make it so that when dashing the dash lines are whatever color the swiftstrike is.
If players are so inclined...
They can help out by submitting skins as well.
Fastlex's pictures:
http://i.imgur.com/YuTFPNt.png
http://i.imgur.com/yfQKq8e.png
Fastlex's skins:
http://imgur.com/MvKMV93,4BSwCN4
http://imgur.com/HKMrMKh,bqpARxH,AXLPoNl
Hexzyle (before I made this thread) produced some recoloured swiftstrikes-
http://hexzyle.tumblr.com/post/51341436651/swiftstrike-recolour
And if anyone else would like to reskin a shield (any shield, not just breaker/swiftstrike) then I'll totally put it here in the OP and give you credit.
If you were going the route of "breaker shield" models for the reskin design, they behave like the SSB does on knights already because of their size and shape. That speeds up the process because the model is already functional.
They would have to make these shields very distinct because people will think they are breaker shields and not your new, cooler, promo box Swiftstrike.
This box would have to show up more than once to be profitable in my opinion. If you give more players more chances to buy those reskinned swiftstrikes, more will buy them in all likelyhood.
Also, what will everyone do with their swiftstrike they already have if they buy a new one? Sell it to vendors or new players?
~Elt