Sadly I have cut Trinket Mage due to Grey Ogres not being very good and a seemingly continual decline in both the range and the number of other good targets for Trinket Mage
Warp deserves a special mention because I was quite impressed by this mechanic
Merlin, Rabbit is the only card that allows you to draw, and while Tiana, Celebrating Princess does provide some benefit to an empty hand, the problem is that every card you draw of the top will cost less than four ink and be fairly low impact
In many cases, cards that play supporting roles in your deck can also double as ways to advance your strategy (Faithless Looting lets you both draw new cards and fill your graveyard with cards you can Reanimate, use to give you a benefit like Anger, or simply make it easier to cast cards like Bedlam Reveler
This spell costs less to cast for each card exiled this way
If you've never experienced the pure entertainment that is the Planechase variant, our primer by Gavin Verhey can get you started