Clint needs to remember that he has had the ability to [SPOILER] since Episode 28!

Every time he hits anybody with any weapon, Merle can imbue it with the energy of a Divine Strike, dealing an extra 1d8 cold, fire, or lightning damage. He could be dealing some real damage, especially against foes with particular vulnerabilities, without expending spell slots! He said he wrote it down at the end of Lunar Interlude II, but I don't think he's ever used it.

As an aside, if Merle reaches level 14 (and somehow continues to play), Divine Strike would deal an extra 2d8 per hit.