So, quick reviews. Will probably have more depth later.

[@Grape] Not bad. Something like wind would probably require a catalyst. (Most magic now a days does in Fate. The ones usually exempt from the catalyst rule tend to be Casters, but they're from a long period ago where magic was more powerful.) I want to see what you come up with for a history and personality.
As for your Servant, I recommend fluffing the backstory a bit. Like of the particular stories about this particular Valkyrie. Lancer's tend to have Magic Resistance (Usually the higher the rank the more they resist.) and as a Valkyrie she'd probably have divinity as a skill. (Which just means she's divine and certain people might be weaker to that.) Also consider your Noble Phantasm a bit. (Some servants have more than one, so you can mess around a bit with ideas. I recommend using Name: /Rank: /Type: /Description: to help you flesh it out more. (Type is usually anti-person/anti-army/Bounded Field, etc. (Bounded Fields are usually some kind of area buff or territory that the servant is stronger in. Anti-person is single target, and Anti-Army is your super move that could wipe out an army.) Also, as a Valykrie consider a skill based around judging others, like seeing lies. 

[@vn2202]
This is more tricky. 
I'm going flat no to Tan Vien Son Thanh. Mostly because Gods, except in rare cases (Chiron, but he gave up his immortality) tend not to show up for Grail Wars. Also, his power just being Earth powers doesn't really endear me to the concept of him. He's probably too powerful, and I have no doubt you'd kill your own mage in a minute with that mana drain.
As for Viktor Muller, he's better. (You didn't copy a wiki page.) But I'd need more of a history, and mages tend to only have one element, not all five. (That's kinda unheard of.) As well as his magic is kinda all over the place. The ability to shape stuff most likely wouldn't be fire related. 
Since I'm guessing you're new to the series, if you need help, just ask and I'll help write down what certain aspects might help you develop your characters.