Mirabel Madrigal - Hopeful Dreamer, an excellent Singer , because of her evasion
For every time you kick the card, you can return that many Creature cards from the graveyard to the battlefield
Hymn to Tourach You need to be a black-heavy deck to cast Hymn to Tourach on curve, but the reward justifies the cost
You don't even need those commanders in play, they can be sat in the command zone while you dump your board full of the most expensive and powerful creatures possible
Both offer a lot in Chaos draft, and combine that with the presence of Heroic (a great cross-set mechanic) and the power level is there
I didn't have the greatest luck, but I did manage to snag a Legendary Tod - Knows All the Tricks from The Fox and the Hound and a Rare 'Do You Want to Build a Snowman?,' which we were able to exclusively reveal prior to the launch of Winterspell