Its Not a Perfect System The system has improved with changes from WotC, but its definitely not perfect
The first set to introduce the mythic rarity was Shards of Alara (2009), and since then, red-orange symbols have been used for mythic rares, MTGs highest rarity
But it loses hexproof for thatit leaps out of the shadows for a moment to stab that enemy, which exposes the assassin
Since the format has pretty much developed into one that's full of mana rocks and other artifact staples, itll be extremely rare that you miss once this rogue hits a random player
And, if youve got nothing better to do on a lazy weekend, by all means - go for it
This is a huge boon for certain Metal types in particular