I voted fire, because im going 80 pach 80 fire 60 light 60 ice.
Going 60 light doesnt make u lose alot of mag dmg.
54 actually gives already a very nice increase: 15%.
At 90 cap light will give 18%. Not much of difference eh?
3% and u have a imbue that does less dmg and is very unstable.
Phantom doesnt increase much with book 2, only 0.5m per 3 lvls.
And speed, just ask for moving march

.
If u leave fire at 32, u will have 8% phy dmg buff.
Fire at 90 gives 18%. That 10% dmg counts. Especially with crits. And u will have mag def buff. AND a
stronger imbue. Which would make up for the 3%.
The only way i would drop fire is to have amazing phy def of the ice buff. And go light imbue. Cause u cant leave light at 30.