Evasion Boosting Skills

Alright, I have some questions about a few skills that boost evasion in one way or another.

I could be incorrect about the following bits, if I'm wrong inform me about everything. But I'm under the impression that:
-Shadow Shifter is a 45% dodge rate (independent from Avoid)
-Evasion boost is similar but 20%

Now there's two skills that I get confused on:
-Illusion Step
-Ignis Roar

The descriptions on Hidden-Street mention avoidability. However, from what I've read about Illusion Step, it sounds like it is similar to Shadow Shifter with an animation. Ignis Roar is similarly worded so I'm not sure which way it leans, but a description I found on this forum mentioned a Dodge Rate.

TL;DR version: How do Illusion Step and Ignis Road work in relation to their evasion effects?

http://www.basilmarket.com/MapleStor...ide-431.html#6
http://www.southperry.net/showthread.php?t=56206
http://www.southperry.net/showthread...l=1#post956568

Thanks, seems I made an error on Evasion Boosts percent but whatever. (More relevant, I was wrong about how it works too, apparently.)

Seems like you're used to such questions, so I'll spare the feeble attempts to defend myself by saying I did use the search (I did, but I didn't find anything quick enough, I suppose.)

Thanks for that, I understand it all now.