Make sure in RTA that you pick Harsetti in 3rd pick locked ban. 

Harsetti allows you to build the most degen builds ever possible as you can now hyper focus on other stats rather than all in on speed. Here are a few examples:

30k hp Ayufine with 3f

30k hp Luna with Eticas (her s2 does upwards of 12khp whilst cycling back around really fast)

40k hp Alencia whilst being incredily tanky and dish out crazy numbers and injuries everyone

Full effective Belian is a nightmare provoking everyone and potentially lowering speed and hitchance every turn

30k hp Harsetti on injury and full damage, deals with tank down and does surpisingly insane damage

Full tank counter DJB on celestine s1 stun and aoe heals by alot!

The possibilities are endless which is why this unit is so scary. You dont know what you are going to fight and your answer to certain units may not work.