It feels like such a flex when you play some beautiful, rare card and wipe the floor with your opponent, or when they do it to you, which honestly happens more often
But declare an attack with JC, and its 10,000 Needles ability balloons it into a massive 10,000-power Freight Train of Death that guarantees it'll deal lethal damage to any creature blocking it or one-shot any opponent if it connects
And because youre still drawing a card with 6+ power creatures, it wont be hard to make sure she continues to grow, draw you cards, and damage all of your opponents
No matter what you discard, theres some value
Also note that you must use mana like normal, rather than Black's typical "you can spend any color of mana" so run things like Manaliths or Fellwar Stone instead of Commander's Sphere and Medallions as your leader
Stand Together is stuffed with Hero cards, and a lot of its play involves making them stronger or gaining benefits when they're on the board