Don't engage enemy tank, if Mal'damba is near him. While you fighting frontliner Mal'damba have time to aim his Cobra Toss.
Attack Mal'damba if he separated from his teammates. It is difficult to aim "Cobra Toss" while under pressure.
If an Evie is coming after you solo, gather around with enemies to avoid being out-flanked. Also, expect an Evie after ice-block to teleport immediately.
Lex is a flank champion, yes but he has a very restricted movement, and he can't move vertically, so he's easy to spot and easy to predict where he's coming from.
so get to a high ground, mine the entrance, and you should always have the upper hand.