According the a FAQ on The Pokmon Companys website, other items lost during migration include cards from the HeartGold & SoulSilver Series, avatar items, certain coins, card sleeves, and deck boxes, the accounts friend list, Trainer Tokens, Event Tickets and the aforementioned coin currency
While running a deck with just permanents that cost two or less mana in Standard mostly limits Lurrus of the Dream Den to very aggressive shells, playing Lurrus, of the Dream-Den as your companion becomes much easier in older formats, which place a higher value on efficiency
These cards are not only visually unique but also released in extremely limited quantitiesespecially compared to standard holo or reverse holo variants
In between those is Zantetsuken, an ability that means "Whenever this creature deals combat damage to a player, that player loses the game." Thats just nasty, especially if you find a way to give Odin Trample or Flying