Remember, two gauges: Matter and Antimatter. Misbalancing the gauges causes Annihilation to deal less damage (particles are left over with no opposite to annihilate with). I'm thinking the skill does, say, 10p per 1/1 gauge spent (total 1000 if both are full), and imbalance means doing 5p per leftover gauge (so as an example, being at 97/70 would mean 70x10, for 700, and then 17x5 leftover, for 85, totaling 785p). If the two gauges ever get misaligned by more than 30 (so like RDM), the smaller singularity will be consumed by the larger, causing a Gravitational Collapse, which locks the gauges in place and can be cast from the same button bind as Annihilation, dealing some consolation damage (less though, it's the Celestial Revolution of the class)
Singularity: generates two Singularities, one Matter, one Antimatter, to begin the 'buildup phase'. Akin to HW Enochian. 5s CD so if you mess up, you can immediately start a new one
Redshift: filler, builds whichever gauge is lower, extends dot by 1s
Entropy: DOT, 12s duration, builds Antimatter
Degradation: 24s cd/2 charges, reduced by 2 per dot tick, builds Antimatter
Solar Flare: 9s CD/2 charges, builds Matter
Nova: 60s CD, reduced by 5 per cast of Solar Flare, builds Matter
Annihilation: consumes all of both Matter/Antimatter gauges, deals huge damage scaling based on gauges at time of cast
Gravitational Collapse: consumes all of both gauges, deals big damage (but not as much as Annihilation)
Haste: 60s self CD, increases GCD speed of self and causes DOT to do it's effects twice on each 'server tick' (including damage)
Quicken: 2min self CD, temporarily increases CD reduction effects by 100%
Slow: party mit, staggers damage from 100% to 90% up front, and then 10% over 6s, split into 2 hits of 5% dealt as a DOT
Stop: party raidbuff, causes specific skills (raidbuffs, basically) to have duration increased by 5s
Syzygy: instantly generates 25 of both Matter and Antimatter
some random timespace themed OGCDs to throw in ala Fleche/Contre, like Comet, generating various amounts of Matter or Antimatter (or both). The CDs of these could potentially be reduced via gameplay too
maybe a targeted teleport mobility tool like shukuchi ('blueshift' lets you move faster in some way?)
and then some AOE-only stuff (one matter/one antimatter generator, which reduce the CD of 'bigger hit that generates both gauges') because SE loves to bloat our bars with 'AOE version of ST tool' and vice versa
maybe it'd be cool to have skills that also consume gauges, such that you'd want to 'skirt the line with overcapping', and use said tools to reduce/modulate your resource generation. The above OGCDs could also fulfill this