I'm not exactly sure why the OP took away all his spells, I would have just left him with whatever the list was in the Monster Manual, but whatever.
In the original thread (now locked), snakeman proposed a rogue to stomp a stock solar. The opposition evolved into two points of view: That a Cleric 20 fait accompli defeats a Rogue 20, and that a stock solar isn't a reasonable representation of an in-game solar. So I created the gimped set up and asked how much needed to be added, ie, how many cleric levels, and/or how much wealth, to make this fight impossible.
Halinn proposed that the solar be restricted to its MM listed items and spell list, and here we are.
I have to admit this far into the argument, it looks like all he really needs to make a mess of things is Summon Monster at will, although I still think with the right strategy the kobold could just power through the solar with a surprise full attack and mock the summons as they slowly vanish. It may require using and/or selling some of the 10 miracle scrolls the kobold has, but you could probably replace them with generally useful items (and not ones specific to this challenge). One commenter in the previous thread said this build has very few sneak attack dice compared to what's possible with even minor optimization. Fixing that makes powering through the solar a lot more possible.
Oh, how about the Solar just makes the shrine completely inaccessible to mundane travel?
That would be changing the scenario, which defeats the point of the demonstration, which was that a properly built sneak attack build is an asset to a low-op party at high levels. The kobold is actually built to be a general threat, you'll notice that it has a variety of items for getting its sneak attack off on normally immune creatures: truedeath, demolition, vinestrike, etc.
So of course, the follow up question is, how would an ubercharger handle the same scenario? Invisible solar, patrolling guards, etc. I'm not sure what build I could propose that would be at a similar level of optimization to the kobold.
(Oh, if you don't mind reading a locked flame war,
the original thread.
Please, I beg you, before continuing that argument, re-read the OP, I tried hard to divert this into something constructive.)