Mystic Sword of the Arcane Ranger into Swiftblade?

[zugschef]

There's nothing that says youneed a level in wizard to have a spellbook.

Although the paragraph that tells how to write new spells in says "wizard" no fewer than five times. The RAW is stupid, but it's there nonetheless. So unless the rules compendium says otherwise, only a wizard can add spells to a spellbook.

indeed, a sotao-char is not able to scribe spells into a spellbook.

i quote the rules compendium:

nowhere does the sotao feat say that you get access to the wizard spelllist. you need one level in a class which does (this can be a level of sorcerer), then you're good to go.

[KellKheraptis]

You could always go the ToAL route and never worry about writing spells again, especially if you Secret Page the whole damn book over a couple years or some such dirty trick.  As a SotAO Mystic Ranger, your first concern should be snagging 9th level spell tech, persist tech if possible, and then becoming god on steroids if you want to be a Swiftblade.  I haven't worked out the feats yet, but I imagine Mystic Shooting Star Ranger 5/Swiftblade 10/Abjurant Champion 5 would be a most excellent gish, with 20 BAB and 20 CL without Divine Power, access to the best spell list, and an in-built action abuse mechanic to keep up with the real full casters.

TL;DR - There are ways around "Wah, can't scribble spells!!one1!eleven!" and it's a secondary concern at best, when you're already a godly ass gish.

[zugschef]

It doesn't have to. You're a ranger. You cast divine spells. The feat lets you cast wizard spells in your ranger spell slots, but you're still a ranger, so you still cast divine spells. It says nothing at all to contradict this, AFAIK.

it's not that easy however...

the rules say:

note that this is a little different from what the rules entry about spells says when it comes to other casters.

A bard casts arcane spells, which are drawn from the bard spell list.

A cleric casts divine spells, which are drawn from the cleric spell list.

the difference is that clerics obviously cast divine spells no matter what the spell is, a ranger however casts spells which are divine. i don't know if it's clear what i mean... the cleric rules imply that a cleric casting these spells makes them divine, the ranger rules do not imply that (at least in my reading). and even if you discard this, the rules say that they are drawn from the cleric/bard/ranger/x/y/z list. sotao spells are from the wizard list, thus the rules must be expanded or maybe even adjusted...

now with the sotao feat a ranger obviously gets the ability to prepare wizard spells from a spellbook (with a reference to the rules about how wizards do that), which use intelligence as the key stat. the rules about preparing spells of either the arcane or divine type again are substantially different. the way a sotao ranger prepares wizard spells is exactly the way a wizard prepares arcane spells and has nothing to do with how divine spellcasters prepare their spells.


conclusion...

without the different way the rules about a ranger's spellcasting open up compared to other casters, and if you discard the matter about the part "from the ranger spell list" versus "wizard spells", the conclusion that sotao spells are divine would be totally and indisputably RAW. if you argue that the rules are simply badly worded in the ranger's case and that the wizard spells are only an expansion to the rules, the case is clear: rangers cast divine spells.

if you consider the way the spells are prepared and the rules text of sotao, which explicitly mentions the connection to the arcane (even the name of the feat does imply this), you could argue that RAI it is totally intended that these spells are arcane.

if you also say that the ranger spellcasting rules do not explicitly say that all ranger spells cast are divine, and that the part about the "wizard spells" is a rules adjustment (and the fact that you do NOT get access to the wizard spell list which makes it even more awkward to rule this a rules expansion), you get to a "dwk/true dragon"-type of argument...