Hello again!

I have one extra question about Greyseer's Lair. It lowers the cost of the first played Skaven card each turn by 1.

Are we playing it right if we've considered to use this property only on the next turn after this card is played? Or does it count itself as a first played Skaven card?

Skaven player doesn't agree with our understanding, so he needs a third-party expert advice

The first skaven card played in a turn is Lair, but its constant doesn't work when it is being played, so: four resources, lair for 4, there already was a skaven card played this turn (lair), chittering horde/death in the shadows in the opponent's turn for free.

Same goes for Master Moulder.