Niv-Mizzet, Guildpact While arguably not even in the top 3 or 4 Niv-Mizzets, Niv-Mizzet, Guildpact has one of the strongest saboteur abilities available
It is a great card to have in the cube, it has loads of nice synergies and it helps increase the overall consistency which in turn increases the overall quality of the games
Essence Scatter might be better as more copies of Stern Dismissal or another bounce spell, but it's to answer creature-heavy decks like Adventures
Its a 3/2 for four that can either blow up a creature or planeswalker, counter a spell, activated ability, or triggered ability
(See?) An effect that allows you to put an artifact card from your graveyard onto the battlefield wouldn't affect Sword of the Realms, however: a modal double-faced card has only its front side's characteristics while in the graveyard
You can check out our guide to Magic: The Gathering Booster Pack types here, but the short version is that Collector Boosters are filled with alt art, foil treated and special variants of cards in any given set