A good card to check when there is an enemy Makoa is Barrier Reef (Link to Barrier Reef image + desc: https://paladins.gamepedia.com/Barrier_Reef) if he is running it at Lv 4 or higher, ignore the shield so that he has to wait longer for his shield.
There are not a lot of things you can do here. Use walls as cover and wait for a flank to kill Nessa is most likely the best solution Using his shield can block a few shots (You can do this if you are really close to capturing the point etc).
If a Grover is by himself, this can give any champion with decent mobility a chance to close the distance between them and Grover. The closer you get, the more damage you do and the less damage Grover does. Don’t forget about the vine though!
If Barik is running One Man's Scrap on a high level try to use CC (To prevent Barik destroying them himself) and avoid the turrets to prevent this form of healing.