More like Lord of Newbs, amirite? Ha ha ha (help me).
Dark Souls 3 boss: how to beat Yhorm the Giant
Your first try at this battle is a bit unfair, because the key to success is locked inside the arena: the sword Storm Ruler is sitting right by Yhorm’s throne.
This sword has a unique weapon art. Hold down the left trigger and it will be embued with the power of the storm; if you hold it long enough for the storm to take – there’s an audio and visual cue – and then attack while in left trigger stance, you can unleash a devastating blow. You can charge this attack up and wait for the right moment to enter the stance and unleash it.
This works everywhere (indeed, if you haven’t yet felled the Rotted Greatwood, you’ll love this sword), but only in the Yhorm fight is it this magnificent. Wait for Yhorm to attack and hit him with Storm Ruler during his recovery phase for whopping damage.
Although his attacks are slow and reaonably easy to dodge, Yhorm has significant reach and closes the distance to you quickly, so don’t ever let your guard down. His second phase is somewhat more deadly.
Make sure you bring some Ashen Estus so you can refill your FP if necessary, and keep your sword charged at all times. The arena is large enough that you can get plenty of distance between you in order to cue up your attack between exchanges.
This battle is, of course, much easier with two or more players, and you’ll find a stack of summon signs outside the door. Look for players who already have Storm Ruler; it has a distinctive curved guard on the pommel.
Additionally, if you have completed Siegward of Catarina’s quest so far, he’ll join you. This really, really helps, and although Siegward can die here, the only negative consequence is the loss of a little dialogue and the knowledge that you were responsible.
Activate the Yhorm the Giant bonfire, and chat with Siegward to exhaust his dialogue and receive some more Siebrau. If you travel away from this area and come back, you can collect his shield, armour and another Storm Ruler. If he dies, you'll get everything but the second Storm Ruler from his corpse after the battle.
When you beat Yhorm you’ll receive the Cinders of a Lord and the Soul of Yhorm the Giant.
Well! Two Lords of Cinder down. Now we can finally go where you’ve all been dying to visit. When you’ve finished shopping, chatting and recovering, meet us at the Pontiff Sulyvahn bonfire.