Honestly I need these cards to come out mostly so I can complete my Cubic Van Halen deck with Soul King Yama, but the new main deck monsters are also bad@$$. As you can see, unless I resorted to handtraps, which I have Impermanence because of Trap Tracks, Unchained still doesn't have enough support to build a full, pure deck. Unfortunately I had to ruin our manly metal theme by adding unmanly gamer girls by shamelessly borrowing a meta engine I found, but they manage to play pretty well together even though the girls don't "play". At least they become Evil. They act as excellent extenders, removal, and hand advantage. My favorite part is that Evil Lil-la can nuke your Unchained trap to net you +1 monster to keep the show going.
I sided 1 Shyama intentionally, because it activates only on your turn, it's recyclable, and you'd ideally want to bring it out when your opponent has a s/t to pop since it already destroys 1 of your cards. But if you find that maining 3 works for you, go for it. I mained 3 Sharvara (and featured him as the thumbnail) because he activates on any turn. Also he doesn't recycle. But he does prevent your opponent from target-removing your Fiend or s/t by "I destroyed my card before you destroyed my card, so your destroying doesn't count, nana-nana na na!" The best part? These dudes have "Soul" in their names, so our links get 6 more numbers of the beast for extra targets. No more waiting on Disaster! King Yama, which only needs 2 Fiends, hence the Cubic crossover, does typical extender stuff. You may want him at 3 since he banishes himself without coming back the second your card is destroyed by anything. So basically you link climb with him on your turn.
Due to the sparse Fiend selection in extra deck monsters, these rockers are limited to Links, unless you want to summon bad. Dharc is not a fiend, but he only needs 1 dark monster, so Soul of Rage can convert anything the opponent has on their turn. Knightmare Unicorn is also a perfect interruption. In fact, you may want to drop 1 Anguish for another Unicorn, because in a competitive game, you are unlikely to ever bring out Anguish on their turn. The link-2 Knightmares are irrelevant to these guys. Thanks to all the new monsters, Underworld Goddess does not look like a pipe dream. It's amazing how much removal this deck gets just by link summoning.
Realize, if you play this deck, you're living in the golden years.