What 5* crystals should I be opening?

Lobster44

I've mainly opened skill/mutants so far, as I was hoping for a massacre/night thrasher for my max 4* domino/darkhawk. I now have both as unranked 4*s, but I'm hesitant to rank them up as I'm not sure 4*s are useful after uncollected, or when you have a rank 4 hyperion for that matter, and I'm reluctant to bring them on quests at r1. I got really lucky and pulled red mags, colossus and blade, so I'm thinking I should probably leave those alone for a while and go for something else. I'm torn between cosmic/tech and science/mystic since I have hyperion but no good techs, meanwhile I have a ton of science class iso clogging up my inventory (I could sell it, but I'd rather rank something up with it). Also, is it still worth ranking up my 4* NT/massacre for synergies or should I prioritize ranking up blade (or keep going for better skills).

unoobmepro

Cosmic/Tech

Open it