You can solve mana with the quipolatl's thesis soul core in gloves in three different ways. First off you'd want to allocate the keystone Whispers of Doom. The curse will be supported by ritualistic curse and spell cascade. For the other supports just choose high cost multipliers such as heightened curse or unleash. Just choose any you see fit. Unleash for self-cast only. The mana regen from this setup will also scale off mana regen and arcane surge stats.
If you're okay with self casting curses every once in awhile to boost your mana regen for option 1.
Option 2 is to automate it with cast on elemental ailment, which also requires you to drop blasphemy, siphon elements(which is honestly not great anyway), and slot in Dialla's Desire into Blink. Automating with CoA/CoC can cause huge frame drops, so beware.
Option 3 is to swap to spell slinger to automate it for much less lag and effects cluttering screen, but requires you to use a dueling wand. This is probably not an option for you since staff and focus ascendancy. Just mentioning it in case, and still useful for others.
If you're not interested in using quipolatl's thesis, then just find more sources of cost efficiency such as a better vertex or passive tree notables. Get rings/amulet with mana and/or mana regen if you can.
Or use the covenant and link comet to Atalui's Bloodletting gem.
As for damage, replace your Rakiata's in CoC with Uhtred's Augury. Rakiata's and elemental weakness is anti-synergy. Have something else besides pinpoint support your comet. You're not using maligaro's so it's not that great of a damaging support. Note boundless energy and energy retention do not count as supports for Uhtred's Augury towards comet.