Now i want to try this out. It combines two of my favorite prestige classes, the war weaver and the spellsword, and refines them to make this. Moving onto an actual critique.
The Hold Spell ability is awesome, though i'd like to see the ability to hold multiple spells as well, though only releasing one at a time, and maybe some expansion on the Arcane Strike feat since it is a requirement.
Battle Hymn is probably my favorite part of this class, reminds me of a slightly smaller, more personal version of the Tapestry of a war weaver, esspecially the Quintessence Weaving (not sure if that's entirely right) which allows putting multiple spells into the tapestry to be cast on everyone in the tapestry at a later time.
And the 10th level ability, while useful, could stand to be given at an earlier level, maybe 5th.
Those are just my opinion so feel free to listen to or ignore it as you wish