"Tempo and Card Advantage" by Eric Taylor (The Dojo) EDT uses the word "pedantic" in the intro to this article and, while it is probably appropriate, the article is still more than worth a read and quite interesting more a decade after its initial publication
If Necropotence is above your budget, this is a pretty great option to replace it
Particularly valuable cards were found in the 'Shiny Vault', which were foil, shiny versions of popular Pokemon, and leading the way in that was this shiny Charizard VMAX
However, from the Scarlet & Violet series forward, every rare card printed in booster packs will contain the Holofoil finish
Until end of turn, that player can't cast spells, you may look at the top card of their library any time, you may play the top card of their library, and you may spend mana as though it were mana of any color to cast spells this way