Yagorath is mainly point tank that can't atack enough in mobile form. As long as you play on Exterminate and have at least one beam she is no danger. You can counter her better if you also have cards that shorten cooldown of your Beam.

Io can stun Terminus by Luna through his siphon. Damage she deals from weapon is higher than from calamity blast and if she bought nimmble she is uncatchable without Terminus' cards on speed. Without his assistance you shouldn't be afraid of him.

His insta heal is big, but only when ally is in his circle. Firstly you and "your allies" should pay attention to "his allies" and them occupy with something. Then when Grover is left alone it's your chance to challenge him on solo fight.

Furia is strong against Lex from long and short disrance. As long as Furia heals are good Lex wins only with damage shooting from weapon. If she uses her skills reasonably and he'll be catched with beam Lex won't have chances to win solo fight.