mtg tempest booster box Magic the Gathering Empty Display 110 rares Tempest Remastered - MTG Wiki

Each one has a strong questing value that forces opponents to challenge or risk falling behind, and then once challenged and/or banished, their effects activate drawing you cards, forcing opponents to discard or return a character to their hand, and more

You stack 3 of these and all of a sudden little Minnie is swinging for 5 damage

The way challenging works is a ready (untapped) character exerts and chooses an opposing exerted character to challenge, and then both cards compare their strength (attack) and willpower (defense) values to each other (meaning the attacker automatically gets hit back by the defender)

If the target creature is an illegal target as Sin's last ability tries to resolve, it won't resolve and none of its effects will happen

Put a stun counter on that creature