Hello.

There are infinity combinations of teams which are really strong. If you are planning to build a scaling team as you stated, the recent skill broken Kushina with Yagura breaks and Kakuzu grudge - edo deidara skill breaks can do their job awesome. Keep in mind, it'll take a while to acquire all these skills and needed fragments, unless you are planning to invest a lot. In addition, you'll need with these ninjas a very solid support team alongside them, because without support they'll have a lot of trouble. For example, Edo Itachi is a must of a support to have nowadays.

Moreover, these teams would also need decent stats on more positions, so they can survive a bit longer, otherwise you'll get one shot due to the stacking meta in our game.

If you don't have Edo Itachi yet and you plan to spend a lot, you can make use of the current synergy with the Fukurokumaru's Deals, investing towards powering up items (Colored Banner Gift with Cave Key Packs/Ninja assist related materials), towards Kushina from the Konoha's Great Tree, or anywhere else you find it beneficial and additionally claim Itachi Edo from the general rebate.

If you happen to have any questions, feel free to ask.

Hope that helps ~