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.
Shell Shield has the longest base cooldown time of any shielding ability and Makoa lacks a Legendary card that reduces its cooldown. Shoot down the shield when possible to ensure its usefulness is limited.
Never challenge Makoa.
Except when you have Crowd Control ability. ( If he dont have LEVIATHAN legendary card )
Or keep a long distance from him while shooting.
It is possible to stun him and kill him in ancient rage. So any crowd control ability can pin him allowing you to either move away or let the team focus damage on him.