New guy. Help please

[Niwashi]

You want to keep your Astral Fire buff up as much as possible. It boosts your damage. But you also go through MP fast in that mode, so when you run out, you need to switch to Umbral Ice, which (rather quickly) causes your MP to recover. The most fundamental part of your rotation revolves around switching back and forth between those two in order to manage your MP resources.

Thunder doesn't add to either of those buffs, but it does give you damage over time, so is good to keep up, at least when you have a very limited number of enemies, or a primary enemy. (It lacks an AoE version, though, so really isn't useful when facing a big group.)

So basically, you want to use Fire until out of MP, then Transpose into Umbral Ice mode and use Blizzard until your MP is back up.

With 3 or fewer enemies (or when quickly killing a particular enemy is important for clearing a DPS check):
You want the fist version of those two spells, which is stronger against a single target.
Keep the Thunder debuff up unless an enemy is expected to die before it would have time to get all the DoT ticks. But don't cast multiple Thunders in a row or your Fire/Ice buffs will wear off.

With more than three enemies:
Fire II or Blizzard II is stronger against a group.
You won't have time to keep Thunder up against enough of them to be useful.

Scathe I've never found much use for except that it's an instant cast, so if you can't get off a Fire or Blizzard spell because mechanics require you to keep moving, then replacing it with Scathe is better than not doing any attack that turn.

Sleep is rather situational. It can help reduce incoming damage which can be useful (particularly with an inexperienced or under-geared tank or healer). But it means everyone has to focus on just the remaining (non-sleeping) enemies. If your teammates want to use AoE skills, or want to put up DoT debuffs on all enemies (Arcanists, for instance, are highly DoT focused), then Sleep won't work unless they scale back their own attacks to just the single target you've left for them. I usually end up not using Sleep in group content unless incoming damage is a real problem where the tank keeps dying. (I'll often use it when soloing, though.)


(Once you get up into your 30's and learn the third Fire/Blizzard spells, you won't need Transpose anymore, since those give you full stacks of the Astral Fire / Umbral Ice buffs immediately. At that point, each switch from one to the other would be with Fire III or Blizzard III, after which you go back to I or II until your next switch or until you get a proc to make version III free of cost.)