[OOC: Spotting someone who is invisible is possible according to the rules. You might tread on grass which flattens because of your step etc., but there also is a 'predator-like' effect when someone is invisible. The DC is 30 to notice there is an unmoving invisble creature somewhere within 30 feet (DC 20 for moving), and pinpointing it increases the DC by 20... in this case, pinpointing Diactum with spot is DC 40. Though hard, within realms of Ilan's capability. Listening is far easier though, and is at this moment only DC 25 - Ilan would easily succeed at this, then look at your direction: even though he can not see you, he knows where you are]
Diactum's skin is greyish, and it seems as though he has gained a few years. His voice is less forceful, his breath more laboured. Since he normally is quite tough (especially for his age) this is quite noticable.
Kheldev also seems to have lost some his luster, though not as much as Diactum has lost.
Suddenly the sibilant hissing voice of the shadowy being can be heard again.
"See?!....I told you so... through many like me you will have to go... many more... all will attack you... they will... they thirst for purity even more than I do... I was pure once... I crave for your pure essence now... your positive energy..." After a long moment of silence it continues "Remember... don't touch the trees..."