Firion's Fin Briar chains PERFECTLY with chizurus phantom shadow!

If you queue up all three abilities and press them all in succession (chiz-chiz-firion), than Fin Briar will land exactly when phantom shadow hits it's 10 multiplier. For an elemental chain this is at the maximum 3x chain multiplier out of the 4x total.

So here's a screenshot: http://imgur.com/vzNx3C9

This is with 557 attack using a death scythe, kazekiri(for chaining) and for TMs, dual wield and blade mastery.

Other buffs/debuffs were impiril, embolden/Elise's def debuff.

Note: this works much better if they are all in the same column of your team setup.