Whenever you learn you can either rummage (discard a card to draw another card) or put any lesson card from your sideboard into your hand
TL;DR: One Piece TCG's official base rarities are Common, Uncommon, Rare, Leader, Super Rare, Secret Rare, and Special, with premium variants layered on top: Alternative Art, Treasure Rare (TR), and Manga Rare (rarest, with very low unpublished odds)
You take Gates over anything replacement level, never pass any of the Gates-matter cards, and just make sure you have enough removal
And it has myriad for ETB triggers to copy like in color Mulldrifter or smashes like in color beater Deep-Sea Kraken
While the "it's slow and bad in a lot of matchups" argument might be reason enough to consider releasing [[Umezawa's Jitte] from Modern jail, it would at the very least show up in sideboards to punish people for playing small creatures