Once the first triggered ability is on the stack, it won't trigger again, even if more damage is prevented and more incarnation counters are put onto it
Personally, I know I could absolutely use that planeswalker in my Mendicant Core, Guidelight Commander deck!
All that for a mana less than Thorn Mammoth, Kogla is the best fight effect stapled to a creature you could ask for
It's still a lasting reason for players to be concerned when facing off against a known Superfriends deck as the Big Bad, but against other decks it's probably a scheme that can be ignored unless a very strong one exists in the Archenemy's deck
It also commits the Voja, Jaws of the Conclave sin of having ward , for some reason
The Swarmlords main payoff is that its always a bit bigger than the amount of mana youve spent on it, which really isnt that impressive