The Thunder way is to kill it before it kills you.
That... pretty much requires you to have had enough PURE SKILL to get Raiko, though. With 85% elemental attack (thanks 50% Thunderbird dude on my FL!), 116% Assault and -30% Def (Mordred with Ambush), I reliably full Burst on turn 5, just before second Overdrive. Thus Stunning her, and then she dies on turn 7.
But Raiko seriously carries the team so hard.
1. Allows you to survive the first Overdrive. This could also be done with Joan, but...
2. +30 Burst from Zeal is just broken good.
But yeah, good luck reaching those numbers without maining Thunder. And even if you main Thunder, bringing Pern to let you live the first Overdrive just won't cut it.