Bolas citadel reads, when you exile a non copy card from your hand yiu draw q card it gains half mans and you lose X life wich is the base cost of drawn card. Now testing this with lolrhs drider, I noted in battle log. Citadel is counting as delt damage not Lose life
Hello @AoMadness,
Thank you for all the information provided, this issue will be investigated!
If you have any additional information that you consider relevant, please don’t hesitate to send me 
Rebeca.