You should be able to solo this without henchmen. Part of the problem is that your deck is simply too large.
As I understand it, you have to fight three storm enemies, each with around 5700 health.
They resist storm, so you'll want to throw prisms on them. They like to cast 35% tower shields, so use an off-school wand to break their shields without triggering your blades and traps.
Storm enemies deal lots of damage, so storm shields are pretty necessary. They do not cast double hits or ongoing damage spells, so the shields should be very effective.
Killing one of these eels early on should make this fight far more survivable. To do this, pack a Feint, and wear a Jewel of the Feint. These stack, and should combine with a prism and blade to destroy an eel quickly. Make sure you keep a storm shield up to blunt damage from your feint traps. Hit with your most powerful single target spell.
After this, heal up, reshuffle, and repeat.
Proposed deck Leviathan Giant (or your best +damage enchant) Storm Prism Sprite x3 Feint Storm Blade Storm Shield (up to 6 if your deck allows) Reshuffle-Treasure Card x3 Feint-Item Card (Jewel of the Feint)
Round Plan 0. Make sure you go first. If enemies go first, Flee and restart.
1. Storm shield 2. If Storm shield is still up, feint; otherwise, storm shield. 3. Repeat 2 until both feints are cast on the same enemy. If you run out of shields, just cast feint(s) 4. Storm blade 5. Use shields or pass until you have pips to cast Leviathan (enchanted).If tower shields are up on your target, use a non-Storm wand hit to knock them down.
**At this point, one of the eels should be dead.** 6. Cast both pixies and any remaining shields. Use wand hits to remove tower shields. Once you have a few pips, Draw and Reshuffle.
7. Repeat steps 1-7 for the next eel, only cast a sprite whenever you have a non-power pip and have a shield up. Keep shields up at all times!
They do boost Myth by a fair amount. The Storm Shields should be replaced by something that instead resists Ice (such as Ice Shield TCs). Otherwise, the same tactic should work.