The tiers aren't about any one specific build.

They're more about the averaged net potential of possible builds for an equally applied degree of moderate practical OP fu. Over a full 20 levels.


The tiers are not strictly linear. Nor does the bottom of one automatically map to where the top of the next, or vice versa. And higher levels of optimization in specific builds can move that build into being comparable to lower optimization builds in the next tier up.


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Sure, needing to spend XP on rewriting your character sheet is worse than just needing to prepare a different set of spells.
On the other hand, it is, objectively speaking, not all that much XP per instance of rewriting your sheet, and XP is a river, so they say. And, realistically speaking, you aren't going to be redoing everything very often, and will usually only need to change out one or two powers known at any given time.

In addition, the built in ability to do that as often as you're willing to spend XP is vastly superior to the inability to do so.


And, sure, an item would probably be cheaper in the long run, but if you've got a long enough stretch of downtime, you can PsyRef yourself into a crafter, and make yourself an item of it - and how far back you can go isn't locked by manifester level, but by how much XP you're willing to spend, and going back 20 levels is only 1000 XP split between manifester and subject, so you can future proof it without much difficulty - and then when downtime is over, you can PsyRef yourself back to an adventuring or other version of your sheet.



Wilder absolutely has a crappy floor. On the other hand, they have a respectably high ceiling, and the native ability to rebuild and go from the bottom of their potential to near the top of it - with just one power that's on their class list. That's not some insignificant detail to ignore. It takes no real skill at optimization or splat diving. It's just there.
The psion/wilder list is pretty decent.

At any given time, the wilder is lower T2, but has the potential to be flexible in ways that T2s normally aren't and T1s naturally are.



The wilder is a bit of a screwy edge case.



But can you really justify native access to Reality Revision and PsyRef as T3 or worse? No need for ACFs, PRCs, splat-searching, or any kind of list expansion, just default access.