I’d look out for two nodes on the Annihilation level.

For farming Realta Alloy at the Silent Field, I’d bring MHX to make short work of the Jeanne d’Arc Alter boss, as well as pulling double duty against the Saber crabs.

For farming the Restored City for Oil, the Tesla boss is a bit annoying due to his NP charge skills and Invincibility Pierce. Kiyohime and Karna offer strong damage and bonuses. While Tamamo-no-Mae (Lancer) or Brynhildr would make the shortest work of Tesla, they offer no drop bonuses. Both versions of Kintoki not only offer bonuses, but they also offer high damage on demand and are versatile enough to recommend as well.