Since we're talking BLU I might as well throw in my existing concept of how I do it... even though I mostly RP it with VERY few people because peoples like to get reaaallll antsy about grey areas of lore (and non existing too) and rightly so.
The method I took with BLU was akin to a parasitic weapon (A Scimitar obviously) that actively seeks monsters and guides the user to them in order to feed on them. Once defeated, the weapon severs and captures the aether of said monster as it attempts to return to the life stream (Much like Odin severs and binds, and much like the process we see in the MSQ with the Ascian and crystal).
The essence of the monster is then stored within one of eight un-aspected aetherical crystals that are set in to the hilt of the weapon itself which can then be called on for later use. Actually calling upon the monster skill itself is a question of the users will to force it to manifest and spoken words of power (In Yangh's case she speaks her native tongue to force the spells to manifest). Every essence will fight and struggle against the user as they are commanded and more so still when they are bound back to the crystal. If the users will is overcome, the weapon then devours the user instead and becomes dormant. Each essence is effectively bound to the user who trapped it and is dispersed when they either die or is devoured.
I went with this method simply because it lines up with known lore (Even though it didn't at the time but luckily it all worked out) and things we have seen and read about in the game itself.
The question of RP balance is down to the delivery as Melkire mentioned. Its a powerful concept and the real challenge is curbing its potentially overwhelming power, which is easy enough done... especially as most of the spells she uses are of protective nature. She has very few direct attack spells.
-takes breath-
I'd also like to echo the advice already given and say that there will be some or perhaps even many who would not be happy with the concept (I've met a few) and that's completely fine. People have opinions, they have their right to them just the same as you having the right to RP whatever you want.
Anyway... just thought I'd share that, might help you or someone further down the road!
Sorry for the wall of text!
The method I took with BLU was akin to a parasitic weapon (A Scimitar obviously) that actively seeks monsters and guides the user to them in order to feed on them. Once defeated, the weapon severs and captures the aether of said monster as it attempts to return to the life stream (Much like Odin severs and binds, and much like the process we see in the MSQ with the Ascian and crystal).
The essence of the monster is then stored within one of eight un-aspected aetherical crystals that are set in to the hilt of the weapon itself which can then be called on for later use. Actually calling upon the monster skill itself is a question of the users will to force it to manifest and spoken words of power (In Yangh's case she speaks her native tongue to force the spells to manifest). Every essence will fight and struggle against the user as they are commanded and more so still when they are bound back to the crystal. If the users will is overcome, the weapon then devours the user instead and becomes dormant. Each essence is effectively bound to the user who trapped it and is dispersed when they either die or is devoured.
I went with this method simply because it lines up with known lore (Even though it didn't at the time but luckily it all worked out) and things we have seen and read about in the game itself.
The question of RP balance is down to the delivery as Melkire mentioned. Its a powerful concept and the real challenge is curbing its potentially overwhelming power, which is easy enough done... especially as most of the spells she uses are of protective nature. She has very few direct attack spells.
-takes breath-
I'd also like to echo the advice already given and say that there will be some or perhaps even many who would not be happy with the concept (I've met a few) and that's completely fine. People have opinions, they have their right to them just the same as you having the right to RP whatever you want.
Anyway... just thought I'd share that, might help you or someone further down the road!
Sorry for the wall of text!
