mtg four color cards Guildgates Matter Deck - Super Strong - 4 - 60 Card - Ravnica - NM/M! 3 Decks to Beat Four-Color

Six mana needs to be making a massive impact on the Modern format and, since this card cares about making other creatures Indestructible, youre probably just better off going with something smaller that compliments the creature

That is often all of what Ophran Viper does

It was the last time you had an amazingly aggressive first turn Dark Ritual combo until 2005, when it was resurrected in Ninth Edition, but by then Dark Ritual was in the past

If the search is simply for a number of cards without stating a quality, you must have them find that many cards (or as many as possible, if their library doesn't contain that many cards)

Blood Rites Those madmen at WotC did it

A foil rare or mythic in the regular frame