Rush encourages mixing colours, as it requires keeping a different colour symbol on the player's field to activate, designated on the card
Those cards were banned as of 1 September 2020
The only people you get interest from are scalpers who want to crack it themselves at a markup, so the best way to do it is to crack it reputably at a reasonable price
Mechanically, Impidimps introduction brought new dynamics to battles, especially in formats emphasizing status effects and type matchups
Unless your opponent gets Heads on flipping a coin, it wont wake up
This octopus advisor will reward you with plenty of life and slowly chip away at your opponents, while all you have to worry about is getting cards from the top of your library into your hand