As they've said, they are still studying it and to be decide if the Invenom will be reduced based on psy OR by the skill defense since poison element is the special element attacks only for dhan classes that should do a damage to targets even its stats are higher unlike other elements, so it may consider that they will implementing it to reduced based on skill defense rather than psy and to transfer its remained attacks to physical attacks as compensation to reducing invenom's elemental damage. So lets wait until the final implementation since korean players there are protesting those Dhan Class over powered physical + elemental damage compared to Templar's only physical attacks since after the elemental talisman + chakra accessories implemented there. and yes they will correct the mana sustain for mana shield and EP, they send apologies through mails, it should be a mana requirement and the sustained mana should be small amount. they will fix it very soon and to be applied on the next patch.