Agatha Cauldron Aetherspark

misleading again, this is actually about [[mairsil, the pretender]] ,

when she etb’s you can exile a artifact or creature card from your hand or graveyard and put a counter on it,

she has all activated abilities of the cards in exile with her counters on.

so if i exile [[the aetherspark]] whatw ould happen?

can i use its abilities willynilly? will she have loyalty? will they not work?