Advice for 5th hero for my fire and ice team

hi all
this is not my decisive team but i just want to mess around with a idea fire and ice combo
counter spell redirect damage.

i only just got a bunch of these guys other day so that why they are low level and low ranks

so i need a middle spot, …

1, first spot red Sumitomo 4 levles
2 blue Boral 4 levles
3.
4 blue boral 4 levles
5 red Sumitomo 4 levles

for choices for middle spot i have for blue i have manga 2 star
sonya levle 1
gunner 1
gravemain 1

plus the ones and two star blue heros maxed out

for red i have

bold tusk 2 levle 36
Zimkitha 1 36
jahangir 2 30
azer 2 22
scarelet 1 12

hawkmoon 1 24
nashar 1 17
Namabage 1 9

plus all the ones and two stars heros maxed out

or i could add others from purple yellow or green but then it would not be fire and ice :frowning:

what hero should work on next to put in the middle spot
i am thinking Zim for bonus regen,

but i would love to know what people think for a middle hero,

finding the ascension items are hard.