Mardu commanders like Ghen, Arcanum Weaver, Jirina Kudro, and Jan Jansen offer unique abilities and strategies, from enchantment recursion to token generation and sacrifice effects
Conjure is an Arena-focused mechanic that automatically creates copies of specific cards to add to your library
If you create a land version of either with Yue and a Clone, you can have it exile itself on entry, before returning as a Clone again to repeat the loop
Obviously these may be a miss for your format for other reasons (power, archetype mismatch, rarity, don't run planeswalkers etc) but here's a few that I found interesting, divided by broad category rather than color: While I'm still not done reading Cosima, God of the Voyage (I'm on chapter 2, the language is a bit dense) these cards are ones I do like both sides of
The [Main] effect of "OP07-096 Tempest Kick" lets you choose an opponent's character to lower cost for after looking at your drawn card
It's often tricky to get the mana right in decks that are more than one color
