IceStorm

Upgrade Path

FrigidAir
⟶
IceAir
⟶
IceStorm
⟶
WhiteAir

Combines to

BigBang
=
Bang
↓
Boom
↓
Explodet
+
FireAir
↓
BlazeAir
↓
Scorching
↓
WhiteFire
+
FrigidAir
↓
IceAir
↓
IceStorm
↓
WhiteAir