Quick general information:
Godsfall
Once again, this is the basic Godsfall. This should allow you to get 8 Shining Crescents off and the third cast of Twilight Waltz if you have buffs. The final cast of Twilight Waltz might be difficult to squeeze in. I recommend using Shining Crescent immediately at 7 runemarks and off cooldown (i.e. Ground Bash isn't worth losing the Shining Crescent or Twilight Waltz at the end). While this rotation is easier than the one that will follow, keep in mind that it is still pretty tight.
Note: The Shining Crescents in the GREEN BOXES may still be on cooldown if you have excess speed so I strongly recommend using filler to keep this rotation as fluid as possible. If -for whatever reason- Godsfall has less than 3-4 seconds left when you get to the RED LINE between Shining Crescent and Twilight Waltz, you should wait for Shining Crescent to come off cooldown naturally (which would most likely be after Godsfall ends) before using second Twilight Waltz reset (unless Twilight Waltz is going to go on cooldown or the fight is going to end very soon).
Basic Godsfall Rotation:
Alternatively, you can begin with one of these openings to start Godsfall burn with full runemarks to ensure that the final Twilight Waltz lands inside of Godsfall for some extra damage:
(The rotation is the same from above after the first Shining Crescent in Godsfall.)
Here is an alternative Godsfall rotation. This focuses on getting both Twilight Waltz casts to fit entirely in Godsfall. I personally don't like this one as 20% increased damage on Twilight Waltz doesn't seem worth the very probable loss of an extra complete Shining Crescent; however, that is for you as the player to decide. There's also a little more information below.
Ragnarok
This is the basic skeleton of our Ragnarok rotation. You want to hit 4 Shining Crescents within Ragnarok and so that means you need to hit Shining Crescent off cooldown. The best way to ensure that you do this is that as soon as you see Shining Crescent hit a 3 second cooldown mark, go ahead and Runeburst > Maelstrom > Gungnir's Bite and you should meet your Shining Crescent as soon as it goes off cooldown.
TL:DR:
Less speed = Less skills cast for Runeburst rotation so you need to be efficient with Runemark stacking
More speed = More freedom to cast more skills and ability to overcap Runemarks
Both scenarios still want to initiate Runeburst at 3 second mark on Shining Crescent.
Basic Ragnarok Rotation:
These are the hardest and most optimal naked Ragnarok rotations. Ideally, you want 6 runemarks before you use Ragnarok so you can skip the first Maelstrom but keep in mind that without excess speed, you won't reach Shining Crescent in time. If you mess up don't be afraid to skip Runeburst altogether - Ragnarok is all about Shining Crescent priority! (Also keep in mind you can always add more or less Runeburst filler depending on excess speed and Dark Herald should be lowest priority.)
Double Ground Bash + Dream Slash:
Ground Bash + Glaive Strike:
For my vanilla valks, there are two options other options.
1. With high physical amplification, you can use the above rotation minus the Dark Herald. The reason being that the extra Dreamblaze from Glaive Strike will end up adding a enough damage to Runeburst in and of itself that the added damage of Glaive Strike is just better in general.
2. With lower physical amplification, you can use the rotation below. This is an alternate variant of the rotation that works very well with vanilla valk and lower physical amplifier because Dark Herald -with its glyph- adds significantly more damage to Runeburst than Dreamblaze at lower amplification levels and because it is so fluid. This is also one of the easiest rotations for valk.
Here is the most optimal Twilight Waltz Ragnarok rotation. You will definitely want 6 prestacked runemarks before doing this as it is pretty tight, but you can get 5 Shining Crescents off during Ragnarok with the right party buffs. Again, do not be afraid to cut Runeburst (or Ground Bash after Twilight Waltz reset) short as Ragnarok is all about Shining Crescent priority! Likewise, do not think that you need to hold onto Twilight Waltz for Ragnarok. It is a versatile skill and best used during enrage - but holding onto it for an extended time is detrimental to your damage.
Build Phase
Now on to building Ragnarok Points! You can build Ragnarok Points by Leaping Slash, Bloodflower and Runeburst spam as well as using Twilight Waltz for Shining Crescent spam. Nothing really has changed besides the fact that with the correct Titansbane Skill Advancement and having it equipped you will gain a full Ragnarok Gauge with every Titansbane - as long as you land the hit. The question then becomes "When do I use Titansbane?" There are 4 times when you should use it. It is up to you to decide when you should.
When shouldn't you?