I tried to include 4 cards for each cost between 2 and 8, favoring card draw and generation to increase consistency in completing the quest. Maybe there's a smarter way to build this but I don't know.

This list is still very much work in progress, since the expansion reveals just started, surely there will be better cards to add.

2 Mana: Possible considerations: Insight, Condemn (Rank 1)

3 Mana: Possibile considerations: Archdruid Naralex, Brightwing

4 Mana: Possibile considerations: Southsea Scoundrel

5 Mana: Possibile considerations: Against All Odds, Steward of Scrolls

6 Mana: Possibile considerations: -

7 Mana: Possibile considerations: -

8 Mana: Possibile considerations: -

After the quest is completed just slam Xyrella+Polkelt or use a Primordial Guardian to draw the shard and win.