|Like most Primal fights, Susano has two phases. For phase 1 of normal mode, he has the following moves and mechanics:
Assail: Non-telegraphed tankbuster. Used after each set of mechanics.
Rasen Kaikyo: Targets several random players and inflicts high damage and lightning resistance down if it hits.
Yato No Kagami: One player will be marked with a red marker, and will be knocked away. Immediately followed by Brightstorm.
Brightstorm: They will then be targeted with Brightstorm, a stack AoE attack, so gap closers are useful here to get back to the group.
Yasakani No Magatama: Summons a Dark Cloud at the edge of the arena. As the fight goes on more will be summoned, up to three.
The Parting Clouds: Used by the Dark Clouds, targets an arena-length line AoE at a random player. Inflicts heavy damage and paralysis. Multiple clouds will all target the same player, and as the fight goes on they will fire several times in a row, up to three, before disappearing. The same player will be targeted for all three strikes, so if you're targeted for the first one you can keep lure them where others won't need to move.
Seasplitter: "The seas part for we alone!" One random player will be targeted for Yato no Kagami and Brightstorm as usual when he says this, but he'll also combine it with Seasplitter, which will strike the entire arena except for a small line that goes between and through Susano and the marked target.
The most difficult part is dodging Seasplitter, which isn't too difficult if everyone remains close to Susano. Take him down to 60% and he will depart for the DPS check phase:
Ame-no-Murakumo: Both the name of the sword and the move it uses, one tank will need to check the Blade's Shadow to receive the Clashing buff and hold the sword at bay by mashing their button. Technically anyone can do it, but the tank is usually best suited. He will do this twice, then one last unblockable time that will kill anyone caught in the AoE and deal major raid damage everywhere else (technically the log shows it twice: Once for the kill version, once for the arena-wide version.)
Sheer Force: Moderate raid damage done by Susano every so often.
Shock: Used by the Dark Levins around the edge of the arena. These will slowly float to the center of the arena and use this when they collide with a player. The other tank should run around and pop these, as the damage is not reduced by stacking.
Basically, for this phase you'll want to have one tank hold the sword at bay, the other tank pop the dark levin orbs, the healers take care of the raid/tank damage and help DPS, and the DPS throw everything they have at the sword. You will have to beat the sword twice before he uses Ame-no-Murakumo a third time to end the phase. Try not to stand in the AoE for that one, it will instantly kill you. Now you'll enter Phase 2.
Stormsplitter: This tankbuster hits much harder than Assail did, but thankfully has a ready time so tanks should be prepared to use cooldowns. DPS can also assist with Palisade or Feint for ranged/melee respectively.
The Hidden Gate: "Earth and stone at our beck and call!" One player will be encased in an Ama-ho-iwato. Two others will also be summoned, the three will be shuffled, and the party will need to slay the correct one to free them in time.
Sealed gate: Used by Ama-ho-iwato to kill trapped player.
Ukehi: Raidwide AoE damage.
On top of all this, he will continue using the mechanics from Phase 1 except for Assail, which is replaced by Stormsplitter. Outside of healers needing to heal more, tanks needing to save defensive cooldowns for Stormsplitter, and needing at least one person good at shell games to mark the correct rock during The Hidden Gate, this is much the same as the first phase.