Folio of Fancies The wheel effects at the top of this list are much more mana efficient and also have that discard element, which can also really matter for decks that use cards like Syr Konrad, the Grim
At a time without explosive monster effects, overcoming Jinzo meant surviving long enough to bring out a monster with a high enough attack, since more common methods of overcoming high-attack monsters such as counter traps like Mirror Force were simply not an option
Amethyst You'll want to use the Amethyst Ink alongside enchantments to gain an advantage to sway the victory in the game
If that creature loses all its abilities, it will still be exiled at the beginning of the end step, and if it would leave the battlefield, it is still exiled instead
As far as the straightforward kill a creature, get a bigger creature card, we have a decent array of Polymorph options just in Blue