Put some other thing in the mix to represent happiness, we've got too much negative emotions in there. But not the staff.
It's hard to define what would represent happiness since looking back she's never really happy, content at most. her only happiness token I can remember is the succubus plushie, and that has already been sacrificed to bring forth SilGoo.
Well, Cerulean likes her adoptive family, so perhaps our own blood instead of the staff or crystal?
That's what Shadenight suggested, actually.
I'm fine with our blood! Blood (sweat) and tears, that's another well known combination.
I'm not sure that this summoning would be benefitted much by the addition of 'happiness'.
What I hope it sees added to it is 'control-ability', specifically a handle that will increase the odds that we can successfully bind it.
Far as happy goes - she enjoyed Lionel. There's bitter in that sweet because of his loss - and that's exactly the sort of happy I'd most like to see added. That doesn't clash with the overall emotional tone, it supports and adds to it. Clashes tend to weaken but I believe Lionel's meaning to her, good and bad, adds a very ideal flavor.
Best of all, Lionel was created because of us, essentially 'by' us - by one under our control assuredly. Cerulean and we controlled Lionel easily. There's already a lot of symbology about us controlling and leading monsters - Lionel was a monster, however weak a one he was. Instead of facing a +25 difficulty to control this summoned thingy, we might be facing only a +12 difficulty, because of the addition of Lionel, or a Lionel-remembrance thingy (any object that was used for or by Lionel a lot and 'makes you think of Lionel when you see it').
Tears of a goo girl, cried over her lost monster; corpse of that monster; robe worn by the killer of that monster; blood of power; plus all the other emotional things that the robe/Mauve means to Cerulean and all the other things she has to cry about...
I see a heck of a lot of power in this, controllable power. However, I do admit it doesn't look like mage anymore.
I think this sacrifice might just give us something very much like Lionel in physical form again, however with changed and vastly increased powers. Perhaps lower in power than an ubermage (which maybe cannot be controlled - if not, that's a waste and a danger to us), but I don't think much lower - and I believe we could control this summons unless we got terrible rolls.
Hm. Actually, a bit of our blood mixed with hers, Chemista's, Psysquid's and the rest? Symbolising family?
Add in Blood, a SMALL AMOUNT ONLY, a -token- amount only!, from us, plus others we -control-.... Sure, it does symbolize family, and if it's a very small amount, I expect it won't change what's coming too much. It symbolizes control too. I'm quite aright with this. As far as blood goes, though, barely more from us than from any other family member. We are supposed to be in control.