Age of Empires II: Definitive Edition

Don't play against a Civ with the Faith tech and not against Teutons at all, they have an inherent convert resistance and get the Faith tech in imp (50% extra Convert Resistance on top of their already existing bonus) pick a civ with bad monks/scouts like Vikings their Light cav (Monk Counter) lack Bloodlines and Husbandry (less HP + No move speed buff) and they even don't get Hussar at all (Imp scouts) should take no time at all, also stop when you are done with this achievement when it unlocks you really want to do the remainder with Aztecs they have by far the best monks in the game their monks get extra hp for every monk tech you do and with all techs is i recall correct their monks get like 100HP

For a map i strongly recommend Black Forest as this map forces a woodline tunnel between you and your opponent if you are worries about losing monks build a few layers of fortified wall in those choke points

To add on what Mr. Invisible posted:
Almost all Civs have the Faith tech.

These ones don't, so pick these as opponent:
- Bulgarians
- Gurjaras
- Magyars
- Tatars