Grumpy Bomb combined with Demolition legendary is a nightmare for Barik, especially if he's with another front liner. That's because he likes to set himself up in one place, and you are forcing him out every 10 seconds.
Ruckus can activate a shield, if you are finding it hard to kill him then purchase "wrecker" from the item shop, getting it to tier 3 shreds through his shield.
Talus is a good champion to flank Dredge. Talus can disrupt Dredges flow of dealing damage and stop him from spamming his AoE (Area of Effect) attacks. Talus should kill him if he can but teleporting back to his portal is still ok as you dealt damage