What should my Eevee evolve into in my Sacred Gold nuzlocke? I'm about to face Falkner and I'm being offered a chance to evolve it into any of its evolutions. It's Docile.

I'm tempted to go with Jolteon because it's a bro, but Umbreon is also tempting for DAT DEFENSE and anything that can take hits well in a nuzlocke is valuable. I already have a Totodile and Chamander.