Should I go tech or skill abyss nexus crystal?

Licky

I'm currently cav, just completed 6.3 and have 3 r5 5 stars, two cosmic and a science (herc, Hulkling and scorp)

I also have one r2 6 star, bwcv

My skill roster is as follows, 5 stars; duped falcon, crit monkey, valk and baron zemo all r4
No decent 6 star skill champs, only winter soldier

My tech champs are as follows; 5 star infamous iron man, hulkbuster and starky all r4

My best 6 star tech is r1 Guilly 2099

My top picks for tech abyss nexus are Nimgod, warlock and ultron

Skill top picks are nf, kingpin and Bwdo

I also have 6 star skill gem

Appreciate it guys, cheers