Lightning, Army of One

First strike, trample, lifelink
Stagger — Whenever Lightning deals combat damage to a player, until your next turn, if a source would deal damage to that player or a permanent that player controls, it deals double that damage instead.

Summon: Brynhildr

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Chain — Exile the top card of your library. During any turn you put a lore counter on this Saga, you may play that card.
II, III — Gestalt Mode — When you next cast a creature spell this turn, it gains haste until end of turn.

Isshin, Two Heavens as One

If a creature attacking causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.