If a sleeve is chipped in a small but noticeable way, the marking can make it illegal to play with in any official tournament
Kassandra was a supremely powerful Commander when factoring in fast mana, and I was regularly able to achieve a table kill with her by Turn 6, with eliminations occurring in conjunction with Excalibur, Sword of Eden as early as Turn 4
While mana intensive, the ability to repeatedly refute an opponent's turn by bouncing their guy combined with the ability to use Disappear as a way to "protect" your creatures in combat (cast Disappear on it and then attack freely, knowing you can save it from lethal damage) made for a very potent enchantment that acted more as a sorcery than an enchantment
As of October 2005, all cards in the Portal block are legal in Vintage and Legacy tournaments
Its also possible that you, like the woman in the back left, are a hanging source of blood
She is a great blocker just on her own, and all the spiders you can draft become pretty solid blockers as well