Which 9th-level spell do you recommend to a 18th-level Sorcerer?

[StreamOfTheSky]

There are certain forms that will be the best for a situation and such. It speeds things up a lot if the player makes up stat blocks of himself in these "common forms" to have ready. They can change once/round, but you often won't need to change beyond the same dozen or whatever favorite forms.

 

[Shin Okada]

Thank you for a lot of suggestions.

Shapechange certainly seems to be useful. But as Runestar has pointed out, it may slow the game down. The player is playing 3.5e for 3 years but recently she seems to be somewhat overwhelmed by the complex rules of higher level spells.

Energy Drain seems to be promising, too.

Shades, while interesting, will not be a good option. The PCs will spend a lot of their time in outer/inner planes. So Illusion (Shadow) spells won't work.

By the way, I recalled one thing. The sorceress knows Arcane Spellsurge. So, she can cast 1-round spells such as Summon Monster IX, with only a standard action. That is something other casters can't.

 

[StreamOfTheSky]

Another very powerful option, IMO, is Effulgent Epuration (so fun to say!) from Spell Compendium. It's a standard action, round/level, etc... abjuration that gives you one floaty, silvery sphere per CL around you. As a standard action, you can move them to an ally within close range to protect them instead. Each orb automatically negates a single spell or spell-like directly targetting the protected creature (as in, won't help with area spells and ones that don't actually target a creature), regardless of its level or any other factor. Utterly devastating to use in a mage duel. Oh, and you can choose to allow spells past the orbs, so unlike SR, it doesn't keep you from receiving helpful spells.
Just thought I'd put forward a defensive option.

 

[Malisteen]

Shapechange really is the strongest, most versatile option for a sorcerer, especially core. Some DMs ban it due to its power. What I recommend is sitting down with a player who wants to use it to agree on five or so forms to use, being sure to avoid balance problems, and then stat them up in advance for speed of play later.

 

[Megahedron]

What are you talking about dude? Meteor Swarm got stupidly broken. They took the broken spell and said, "No, we need to make this better." As for recommending. It's hard to tell based on the information you gave us, but I think it would be based on how he made his character. But look in the spell compendium, it has nice things that often get overlooked.

 

[Runestar]

What are you talking about dude? Meteor Swarm got stupidly broken.

If by broken, you mean that it does not work as expected because it is too weak, then yes, I agree with you. But if you are claiming that meteor swarm is too powerful a spell, then you really need to justify your claims, because I have found it extremely underwhelming in my games, not least because fire resistance applies 4 times (and quite a number of foes at that lv will have fire resistance of some sort).