im thinking a crossover module?
like the type where there is both energy and heat. i think we had them in the legacy days (cant rly remember). i dont know how the stats should be since im not that great and i only own epic to legendary modules. ill just judge from legendary
(unupgraded) legendary stats
heat capacity: +24
energy capacity: +24
since legendary modules give 48 of their capacity and 22 of their regen/cooling, i halved them since putting 1 heat module and 1 energy module is the same as putting 2 of these. again, i cant judge mythical stats because i dont own any mythical modules. sry if that causes inconvenience :3