Okay being on the game since launch I really should of known dots make use of the damage increase. So yeah your right, just gonna throw the number down though to see how much better it is. These are all following the use of Suiton --> Trick Attack.

Okay time for some maths, Skill : potency [10%].

Melee Combo

--> Mutilate : 360 [396] - 2s -> Spinning Edge : 150 [165] - 4s -> Shadow Fang : 240 [264] - 6s -> Spinning Edge : 150 [165] - 8s - Gust Slash : 200 [220] - 10s -

1210, 110 additional potency.

Ninjitsu Combo

--> Mutilate : 360 [396] - 2s -> Kasatsu - Raiton (2 - 3 second to set up / cast with Kas no cooldown) : 360! [396!] - 5s -> Spinning Edge : 150 [165] - 7s -> Shadow Fang : 240 [264] - 9s -

4 Abilites were used here, although a 5th (spinning edge, assasinate, mug) may be able to be added depending on your ninjitsu speed.

1182![4] or 1345 (Spin), 1336 (Mug), 1402 (assasinate [if its available]), 111 [126] [125] [131] Additional potency.

safe Below 20% combo.

Mutilate : 360 [396] - 2s -> Spinning Edge : 150 [165] - 4s -> Gust Slash : 200 [220] - 6s -> Aeoilian Edge : 320 [352] - 8s - Assasinate : 200 [220] - 9s -

1353 Potency, 123 additional potency.

Conclusion

Until we know the exact time it takes to accurately perform Kas --> Raiton (Kraiton) we can't be sure on the best burst potency, although there is at least a safe option that cannot fail.

In the anniversary video it takes them 3 seconds to perform Kraiton, but they do appear to add in a large gap that by all accounts could be removed.

Either way 1350 potency over 10 seconds isn't too bad, this isn't including the 400 done before hand. (Thinking about Odin in 2.5, that last dps check below 20% is going to make Ninjas a must have for most parties.)