Iris

Friends, I'm planning to play with a friend, and we'll be using Iris as our late-game hero – the one who trains griffons. I want to use a tactic with Battle Griffons, Defense, Readiness, Dark Magic, and Vampirism. I'll train Lancers into Inquisitors. We'll play defensively, meaning we'll shield a large stack of Inquisitors (the ones that negate positive effects from enemy units with their attack) with griffons, take a defensive stance (with Readiness, the griffons will attack any attacking unit twice, and each time with 1.5 times the strength until their turn comes (the Battle Fury skill), and they'll sustain themselves with Vampirism twice), and the Inquisitors will assist them.
From the skill branches, I'll take Light, Dark, Luck, Defense, and Leadership.
Is this a viable strategy, or are Laslo, Axel, or Miv still more impressive in the late game?