How to deal with Amorphous Gel (chapter 1) using a team of fiends?

If you're in a New Game Plus, then you can capture Lulu in Besaid using an SP pod. She comes with abilities "T. Fire", "T. Blizzard", etc. which cast an elemental magic eight times on random enemy targets. Otherwise, I might just start with some fiend like a fire elemental and add other element magics.

Still, at low levels, the fact that they will cast elements at random makes it very iffy whether they will happen to select the right element in time before that fiend party member is wiped out - especially if you're still at low enough levels that eight hits won't be enough to defeat the gel, or if you're using an elemental caster other than Lulu.

Another ability that I might consider trying would be Sparkler - though I don't recall whether that would be available to learn in Chapter 1 of a non New Game Plus. Similarly, Momentum might be good if you're in a New Game Plus and have items or grid spheres left over to teach it - though I'm not exactly sure if the mechanics of that will work out, e.g. whether or not the enemy defeated count carries over to a New Game Plus and whether or not each new fiend party member would have its own enemy defeated count. In the past, I've also had good results from equipping a Cat Nip on a fiend (also obviously requires New Game Plus).

To be honest, I usually just have my low-level fiend parties flee from encounters with an Amorphous Gel. (This is possible by pressing L3 three times until there are no stars remaining on the top bar and the message reads something along the lines of "I give up." Just note that your party members will still wait until they have executed any queued actions before escaping, which can result in one or two party members still falling if those actions were scheduled after enemy actions - so do this quickly at the start of an encounter.)