Ygraine is a giant, standing fully thrice the height of a comparable human but being otherwise similar in general body-plan to their kind. As she is from the miniature plane of Segovia, this means she is just over two inches (51mm) tall. She is fit and somewhat muscular. Her skin is pale and heavily freckled. Her waist-length hair is dark auburn and kept in a loose braid. She has a somewhat high forehead, smallish nose, and slight overbite. Her cheekbones are somewhat high. Her cheeks are full. She has somewhat narrow shoulders and hips. She wears a close-fitting, stiff, dull red-brown dragon-leather vest over an emerald, woolen shirt, and a heavy dark-brown pleated leather knee length skirt with steel studs, supple leather gloves and heavy calf-high boots. She carries a compound dragon-bone bow, strung with dragon sinew, a quiver full of steel arrows, and a one-handed steel sword. Alternatively, she may wear a pearly white silk toga (cut from the pillowcase of an orzhov clergyman so she could have a change while she washed her normal outfit).

Compared to a full-sized person she is very strong (able to lift a significant fraction of her own body weight with relative ease), is very good at jumping and climbing, is relatively durable against abuse from much larger foes, and is able to survive very long falls (many, many times her own height), at least when on a plane other than her native Segovia (due to the havoc outsiders tend to cause, studies of the physics of native Segovians in their own habitat are rare to unheard of). Objectively, though, she's two inches tall, which means she would have great difficulty competing physically against folks in the "four foot and up" range, or even a housecat or particularly large and ferocious rat.

Ygraine was a lone warrior on Segovia. She honed her her martial and magical skills, and when a need arose she would employ them both for her own glory and the aid and protection of the little folk. Though there was always an edge of altruism to her actions, she got the most satisfaction from the recognition such behavior earned her, the idea that not only was she large enough to make a stir just by existing, but also that everyone would know her name, that people would praise her for her great strength. As such, Ygraine kept moving, looking for more ways to earn the praise she so fiercely desired. In the end, she found she best made her name as a dragon-slayer, and hunted down marauding wyrms and hellkites across the length and breadth of the land. After one particularly difficult battle, Ygraine found herself atop a high mountain, great vistas spreading out around her in every direction. She raised her arms to the heavens, cheering for the sheer joy of being there, triumphant, at the top of the world...

And then she found herself atop a breakfast table, staring into a face with eyes nearly as large as her entire body. The titanic child opened its gap-toothed mouth, and reached out for her with a chubby hand. Stark terror brought Ygraine to another strange world, no less gigantic than the one before, then another, and another after that. Everywhere she went, Ygraine had become terribly small indeed. The former giant was no larger than a mouse, and was now obliged to hide lest she be crushed underfoot by the sort of people she once looked quite literally down upon as they heaped their praises up to her.

Ygraine's first days in Dominia at large were very unkind to her. Lost, confused, and for the first time in her life afraid, this is when her significant intellect taught her to appreciate and apply the knack for blue magic that she had long neglected. It was easier if these big people (and cats -- especially the cats) didn't see her, and from there she devised an arsenal of trickery to keep herself alive. It was working on a spell to level the playing field should she be forced to fight for her life, having seen a local wizard utilize magic to that effect, that Ygraine came to the realization that mana did not, in fact, have a size. While she had learned to utilize fire and lightning, roots and vines, and all manner of other efects on her own scale, with some effort the same spellcraft could function on what seemed to be the normal level for the multiverse: there was no strict need for miniscule Ygraine to conjure miniscule attack spells. After that, hostile felines were far less of a worry, even if casting "full scale" spells was an immense degree of trouble.

It was time to show the multiverse just what she was capable of.

Ygraine has a narrow but potent ability to utilize red, green, and blue magic. Most of her red and green spellcraft is focused on ranged attacks: While Ygraine was very strong and imposing on Segovia, that wouldn't help her much if a dragon took to the skies, so she either had to pull it down, shoot it down, or follow it (more than once she decided to jump on one's back.) Since becoming a Planeswalker, Ygraine has embraced blue magic, learning to do such things hide herself or shrink her enemies (though unreliably). Additionally, she might now poison her sword or arrows, or use other sorts of tricks that would allow her to successfully combat foes with a greater size advantage than any dragon had ever held. Since learning how to cast the occasional spell on Dominia's scale she might have let that slide, but she's found a certain attachment to being able to handle matters with her "natural" abilities

Ygraine is a glory hound for one -- desiring the adoration of the masses an the appreciation of anyone she might think of as a peer, but more even than that, she is stubborn. She could probably find her way back to Segovia and stay there, but since she's decided she can survive in the larger planes, Ygraine won't set one foot back on her home at least until she's proved to herself that she can. While she's clever enough to try different approaches, she won't give up on a goal once she's set her mind to it, no matter how long it takes or what kind of hell she has to go through to get there. When confronted with failure, she is vastly more prone to anger and defiance than to depression or acceptance, being firmly of the "make life take the lemons back" persuasion. She is very emotional has a hot temper in general, which sometimes interferes with or obfuscates the fact that she's smart, making her easy to underestimate, even for Segovians, since few would expect the boisterous woman to be able to out-think them in a pinch.

Despite her many faults, she is generally a good person -- if all she wanted was respect and worship she might have taken the tyrant's path rather than the hero's: she was strong enough, but she wanted to do the right thing as well as the thing that would get her what she wanted, even if it was harder, and she feels some satisfaction in helping people even before she is recognized for it.

Typos:
"She has narrow somewhat shoulders and hips."
"and with some effort" should not start with a conjunction

Suggested rephrase:
"to appreciate and apply the blue magic she had long neglected her knack for."
to
"to appreciate and apply the knack for blue magic that she had long neglected."

Massive Mana Explosion of the Dragon Hellfire Tempest Inferno - (no mana cost)
Sorcery
Suspend 3 -
Massive Mana Explosion of the Dragon Hellfire Tempest Inferno deals 1 damage to each creature.
"That was it? I knew it. Never buy a spell from a Segovian Peddler-Mage."