Learning how to properly play AST

[Rongway]

Once you get to 60 you can do this thing...
Synastry -> Collective Unconscious -> Swiftcast -> Aspected Helios -> AoE Card Buff -> Aspected Benefic -> Time Dilation -> Celestial Opposition -> Cleric Stance -> Luminiferous Aether -> 20x Gravity
and as long as you don't have a DRK, you can stand (float?) there casting Gravity forever without healing the tank and without running out of MP.

Synastry increases Collective Unconscious as well? I didn't know that, I thought it just increased actual magic spells not abilities? Would love to find out as I didn't realize that, otherwise I'd use it before CU often then.

No, I use it there because Collective Unconscious takes up to 3 seconds to apply itself, and don't want three seconds of Aspected Benefic ticking away while I'm waiting for Collective Unconscious to take effect. For me it's purely a timing issue, not because it gets bonus potency (it does not). You could also swap Aspected Helios and Collective Unconscious to take advantage of Aspected Helios having the longest duration, but I prefer to Swiftcast+AspectedHelios as I'm running away from the danger I might have just put myself in by running to the tank. Again, timing, and your situation might be safe to do Aspected Helios first.

Wait a sec lightspeed do not make your spell instant it reduced the cast time
Aspected helios still have a cast time (suuuuuuper short but still forbid you from using while running)

Be careful with this spell
Look awesome but you burn your mana even with -25% comsumption

It still gives you a short enough cast time that you can cast anything except Ascend while on the move.

If you use Lightspeed as an Oh Shit button, remember that its full potential lies not in making your heals instant but rather in allowing you to perform actions in between heals without costing any time.

I don't entirely agree with this. You're forgetting to mention that Lightspeed lets you cast while moving for most spells. I use it all the time, can run to one end of the arena, pop Helios, and then to the other and do it again if necessary. Great for those instances where people are spread out, especially since it reduces MP by 25%. 90% of the time I use it it's while running or moving.

I respectfully submit that, yes, while it is useful in this situation, aside from explicitly split-party battles (ex.: Fist), the real problem is that everyone else should take more care not to be so spread out that you have to use two heals where one should suffice.

Something I'd like to see happen is people learning that when there is an AST in the party, they should be close enough for an AoE buff to hit everyone without us having to ask them to (Gather together.); this would relieve issues with missed AoE heals as well.