Currently, I see T2 players using it. This is fitting, as it is a T2 item, but lets ask ourselves- Is this an item for new players? I'd say no. That new players should learn how to use a shield more, that swiftstrike is an ultimate of sorts for the glass cannon playstyle. It isn't just a normal shield that should be attainable within minutes. A lot of these players view the shield requirement of the hall of heroes as a tremendous joke. Why should they get a 5* shield when they already the best shield in the game?
It should cost 30 tokens from each boss. That would ensure that players would value it, that it would be sought after, and that it would be a rarity. But it would still be attainable after a bit of work, which is how I think items should be for the most part.
Players that already have one would keep it, and players with the recipe learned would be compensated.
" Why should they get a 5* shield when they already the best shield in the game? "
Because they have to, Tier clearance :P