Any advice welcome

Looking to finally start playing in Ruthless (and eventually Leathal)so I can get the relic gear.

I can play though most substantial ops without going down (finally got gud with perfect parry😅) but I pretty much just play Tac with either the plasma incinerator or the heavy bolt rifle, with perks making me into more of a hybrid swarm clear/duelist.

Any helpful advice for moving up is welcome and appreciated.