You would have to add cards like Reshiram or Bouffalant or some other non- EX and that would just completely ruin the consistency of the deck
If your main goal is to build a collection to play Historic, it will be wise to pick packs that offer the cards you want for constructed
I think Copy Artifact would be more useful, perhaps even Phyrexian Metalmorpth and those are just more examples of cards that are a little too situational, slow or hard to cast to be worth it
Four full-release Un -sets have been released so far: They are Unglued (1998), Unhinged (2004), Unstable (2017), and Unfinity in 2022
You will have various types of removal, perhaps mass removal, creature removal, countermagic and non-creature removal or something
It is a very weird card but, at the same time, also a very captivating one with a style not usually seen in the Pokemon TCG