Mage/Dark Wizard Lament Riftwalker Improvement

I used this build in 1.20 and tried using an Ability Tree with it in Beta, but I wanted to know whether this can be improved for 2.0 without changing the playstyle completely (Lament, Time Rift and Riftwalker should stay).
Also, is the Ability tree fine as it is?

The build:
https://hppeng-wynn.github.io/build...0K40og0Qk0A112C0y0A1g00001004fIzz++++-t+s-UpH
WynnBuilder build:
> Sparkweaver
> Time Rift
> Vaward
> Stardew
> Detective's Ring
> Moon Pool Circlet
> Prowess
> Tenuto
> Lament [w6w6w6]

 

https://hppeng-wynn.github.io/build...K40OM0Qk04112C1V041g00001004fIzz++++-tzjptRC1
WynnBuilder build:
> Cancer֎
> Time Rift
> Steamstone
> Stardew
> Finesse
> Finesse
> Prowess
> Diamond Hydro Necklace
> Lament [w6w6w6]
This tree goes full riftwalker, but you can mix in lightbender if you like it
edit: you can use a summa to cancel the -mr

 

https://hppeng-wynn.github.io/build...K40ty0Qk0C112C1Z0C1g00001004fIzz++++-t+sEtzJ1
WynnBuilder build:
> Cancer֎
> Time Rift
> Vaward
> Stardew
> Summa
> Summa
> Prowess
> Amanuensis
> Lament [w6w6w6]

I decided to change the skill tree by getting rid of cheaper meteor, exploding teleport, winded snake and fluid healing for earth master(i need this for manastorm), manastorm, burning sigil, and stronger meteor. Manastorm gives a lot more mana, like it can like reach up to 20 extra mana a second if spammed at 2 spells a second after 5 seconds of spamming spells. I also probably overkilled the mana steal, so it might be able to reach more dmg. I hope this build is good as I'm just a beginner at building class builds.(Thanks DeltaWave for giving the idea to use Cancer lol)(I would love someone to critique my build if it's not the best)

 

You are losing fortitude's dmg buff and purification, but might get more dps in the long run. Good tree tho

 

How long does fortitude's dmg buff last for?

 

5s, 15s cooldown
its good becouse it helps when in a team

 

I played with your build for some time and I must say, that I really like it. EO was shredded by it and it performed well in LI, except for the Virus Doctor. The mana sustain is not too high, if you have a single target and fast moving boss like Dr. Legendary, so it works fine for me. I can not decide whether the damage is good, because I don't have a good comparison in 2.0.

I did some small changes to the Ability tree though to give me access to fluid healing, because Lament gives a lot of Water Damage and because I use heal far to often. Fluid healing gives my +1200 hp per heal while having to sacrifice 500 meteor damage, because of water mastery lacking. I also removed Devitalize to gain AP (thunder mastery makes up for Riftwalker points).

Overall a very viable and fun build. Thank you!