Strategies that rely on drawing heavy amounts of cards also win from cost reduction, especially impulse draws from cards like Escape to the Wilds and Commune with Lava that allow you to draw tons of cards
And when this card leaves the field, you can also shuffle any card on the field into the deck, just in case you needed non-targeting removal as well
One more thing about the distinction between personal copies and spec copies: We dont tend to worry too much about the cost of the sweet card we put into a Commander deck, at least as it comes to new cards
Take 1 "Seventh Barian's" from your hand or Deck and place it face-up in your Field Zone, also until the end of the next turn, you cannot Special Summon monsters from the Extra Deck, except Xyz monsters
But since it is also a promotional card, it's banned from the official tournaments