Evangelist past 10th level

[Iron Giant]

I'm a bit unclear on what happens to a character when they hit the level 10 prestige class ceiling. I assume that most prestige classes require that you take some other class/prestige class since there is no level 11 to go to. While that seems straightforward enough, what happens when an Evangelist (or to a lesser extent any prestige class that furthers spell level progression) hits this barrier? e.g. If a level 5 wizard/level 10 evangelist levels up and he decides to pursue another level of wizard, does the 6th level in wizard retroactively rejigger the evangelist aligned class ability thus giving him the BAB and saving throw bonuses granted at wizard 6, but the spells/specials/etc of a level 16 wizard? *or* does it just grant you level 6 specials that you already have? The latter would obviously mean you wouldn't want to return to your original class.

[MurphysParadox]

The relevant text: "She still retains the Hit Dice, base attack bonus, saving throw bonuses, and skill ranks of the prestige class, but gains all other class features of her aligned class as well as those of the evangelist prestige class."

Pretty straight forward - you continue to add the 10 evangelist levels to the wizard levels for calculating everything mentioned above. Basically, you gain the hit dice, BAB, Saving Throws, and skill ranks of a level 6 wizard and the features of a level 16 wizard.

[Nefreet]

I like "rejigger". Let's go with that.

[Zilfrel Findadur]

Just take more standard classes levels done.

[Isil-zha]

Minor correction, you only add Evangelist levels beyond the first to your aligned class, i.e., a maximum of 9. Which makes sense as the feature is gained at second level.

ISG:

She gains all the class features for this class,
essentially adding every evangelist level beyond 1st to her
aligned class to determine what class features she gains.