OK, this is a stab in the dark at the most difficult stuff to do: a Traveller line.
It borrows or directly uses cards and ideas of Asper, Cookielord and Multitalented.
Drunkard is a card by Cookielord.
Serf is incredibly weak. It features the 'mess with the time' mechanic of
Asper's and Cookielord's Plantation which matters for Friar.
The card is obviously extremely bad in order to compensate for the second card in the line being a pretty good 3 (which is not the case with official Travellers).
If it is too bad "take 1 Debt" is the buff. Thematically Debt is in here to somehow represent feudalistic structures.
Freeman is a straightforward village version of
Multitaltented's Detain (wording is directly from
Theta's version)
It is probably a pretty good 3, if not a 4, and you might very well wanna keep Freemans in your deck if you need villages.
Thematically our Serf has now become a free peasant.
Friar is the most complex card. Early in the game this trashes and gains a little bit of something for your economy (Novices are one-shot Peddlers), very late in the game it gains a Duchy or something better and during the middle of the game it makes it harder for opponents to call cards which matters for Cardinal. This doesn't scale uniformly with player count, Beer compensates for Drunkard in a 2 player game but with 3 players you have on average 1 Beer and 2 Drunkards on your mat. Also not sure about whether the card should get the Attack type.
The window for exchanging this is small and you gotta consider whether you wanna keep a Friar in your deck in order to make opponent's Cardinals weaker.
Thematically our Freeman has now joined a monastic order and is all into beer-brewing.
Abbot is a bit like Golem, expect for the fact that it doesn't dig and also thrones Treasures. If there is junk on top it could also miss. So it is a tad weaker than Golem.
I am not sure about
Cardinal yet, its permanent effect could be too strong relatively to calling this (keep in mind the Drunkards) in order to get a second turn. Calling and trashing this for a Province might be too automatic and/or too strong.