- Melfice is probably the one who put them there after stealing them from a guarded location on Arachna, but we don't know quite how long he has been in Cyrum. Long enough certainly to be in the King's confidence, but it's possible that the Claws just haven't had time to have an area of effect yet. Especially as the Claws were implanted into Tio who was placed under Cyrum instead of being 'out in the open' on the surface like, say, the Tongue or the Eye.
- Tio is not human. Without a soul to feed on, the Claws haven't enough power to do much more than sustain itself and can't waste time expending energy on effects in the area.
- They did have an effect; but only just within the Castle and its area, and it's not yet noticeable. With Melfice there to push it along, the Claws' (and Horns') influence had an effect on the King's mind, making him want to make Cyrum a military power again.
After all, at the end when Elena calls her forth from her own body, the Songstress and she recognise that Millenia was always 'a part' of Elena.