I currently have mad inventor and axe punisher, now, I don't know any specific build that works, but with that said, here is what I think:
Mad inventor- a great hero, mostly made for dmging heroes and buildings, think of him like a mini cosmo,he's pretty good if you set him up correctly, a decent use of recourses too.
point count for mad inventor:
7-10 for base destruction.
5-10 for tankiness.
9-10 for hero killer.
10-10 for arch demon.
7-10a good hero, but has its flaws.
Axe punisher:now I'm quite pleased to be a owner of this hero, it is very useful and I like him, he's great for base destruction and even hero killing!(If you want to go that far.)
Point count for axe punisher:
10-10 for base destruction
7-10 for tankiness
8-10 for hero killer
9-10 for arch demon
8-10 it's a amazing hero, and I can't stop using him, it's super amazing how he wipes bases quickly.
Of course this is my opinion, if you think something isn't right or just want to point something out, feel free to reply, but for now, that's my overview of 2 of the 4 new heroes, hope to see my self doing this again in a week with another new hero. Stay safe!