The ever-looming threat of Gargos, an 8/7 creature, fighting an enemy creature is enough to put off many opponents from targeting your growing army of Hydras
When your opponent does play a powerful creature, use a removal or counter spell to get it into their graveyard and boom, pay a paltry amount of mana and that puppy rises again, but this time on your side as an unholy abomination of itself
Technically, its on the front side of a red card, but whether its going to be an anchor in creature-based 60-card decks or utilized for all its worth in EDH, this is a really great Magic card thats useful in all sorts of situations
#2: Swords to Plowshares Like Lightning Bolt, some cards can end up near the top of the list by doing that which you want most, but far more efficiently than any other card in the game
Apparently whatever the luck of the RNG gods says it does