This is an hybrid build, aimed to getting x12 combo, using the heavy and then building up the combo back up. [Focus Energy] is used to increase the heavy atack efficiency while also adding a bit of raw damage, as slash weight is extremely low on [Pennant] and will mainly proc slash from heavy atacks. CO can be swapped for sac pressure if not priming at all.
[Focus Energy] can be swapped for [Reflex Coil] (it will increase the dps over level 1k by a really small ammount, which is better than nothing)
If not using dextery arcanes and if you are struggling with keeping up with the combo duration, swap [Focus Energy] for [Drifting Contact].
Alternatively, you can go for a pure heavy atack build, swapping [Focus Energy] for [Corrupt Charge] R2, CO for sac pressure, [Blood Rush] for sac steel and [Gladiator Might] for [Killing Blow].
Keep in mind that [Wise Razor] is an awfull stance, so you shouldnt use many regular atacks. CO is there only to boost the reg atacks, not the heavy (as the heavy calculates the dmg as ppp * combo counter+CO)
NOTE: [Pennant] isnt one of the good melees due to its low slash weight, the heavy build will work better for higher levels, the hybrid build is just to make use of its passive