Okay you have watched a silly in game advert and you have been told you have a five minute monster boost. So what? Well so plenty!
First for the next five minutes every floor from onwards will have an enslaver who may even drop legend or eternal pets. So get your farming gear and speed kill enslavers for 5 minutes.
Any challenge map (including legend etc) opened on floor 1 will contain 2 cartographers and 1 enslaver. So you get 2 maps per floor which halves to time it takes to complete the kill cartographer and collect maps feat to drop a legend map. If you have the accomplished perk thats 9 floors to make 18 maps. Make sure you complete the feat on at least floor 100 to spawn a high level map. Then convert it to a higher floor if you want. Just don't convert a legend map dropped on floor 10 to because you will drop low level legends