Fifth Edition Foes was worth more than the Kickstarter price I paid for it. I use it often enough that I really need to get the PDF printed and bound...
They deliberately delayed release until after the MM was released so they could fine-tune balance. The wonderful thing about the book is that it's inconsistency in attacks and powers and adds a refreshing style change from the core rules. Last session, I threw a Red Jester at my party. His primary attack is a Mace of Mirthfulness (or something alliterative like that): on contact make a will save or sing and dance for a turn (David Bowie had just died, so everyone had to do "Dance Magic Dance"). His secondary attack was more interesting: a bonus action to chuck a card from a Deck of Many Things at a PC. As luck would have it, he only dealt good cards. Lucky party. The Deck drops from his dead body as a plain deck of playing cards.How closely does this book hew to the final 5E rules? I did not back it because I was worried about compatibility.
They deliberately delayed release until after the MM was released so they could fine-tune balance. .