Two mana for a 2/2 that gains you a life when it attacks is decent, and enables a lot of life gain synergies
If you're not just using him as a bad Aethergeode MinerAethergeode Miner, however, I do really like RexRex
It costs 3 generic and 2 Red mana for a sorcery that makes each player choose six lands under their control and sacrifice the rest while also dealing 6 damage to all creatures
But much like Kaalia of the Vast and Zur the Enchanter, Narset has a powerful attack trigger, rather than a combat damage based one
Play it in decks that want to draw a bunch of cards, wizards, or combos
A spell cast using harmonize will always be exiled afterward, whether it resolves, is countered, or leaves the stack in some other way