i like this idea, but it seems kind of hard to word like you said, the way im explaining it to myself is a iridium warden for pillars.
My question is, will the siphon be the same as the pillar you target or same as your mark? if it was the target then it would be a nice card in a rainbow or mindgate deck, if it was your mark then it would be insane because it would be like a devourer with a neutral cost so basically quata denial for every deck XD
maybe the siphon effect could have a cost but a double effect, so like pay 1 water siphon 2 charges of target pillar and delay it or maybe you only get the quata on their turn when the delay wears off.
its a tricky card for sure but i hope this goes somewhere goodluck!