Some info on how this ability snapshots:
Consuming a Bloodtalons charge with Ashamane's Frenzy will buff all 15 hits with BT.
However Savage Roar and Tiger's Fury do not do the same. They are snapshotted on each individual hit, so if either TF or SR fall off during Ashamane's Frenzy then the subsequent hits will not be buffed by them. Ideally you would consume a BT charge and cast Ashamane's Frenzy at the beginning of TF to maximize it's damage.
BIG NOTE: You must stay in range of the target and have the target in front of you. This ability is "channeled" however you can cast other abilities while it is active. Essentially you do additional swings which trigger and extend the dot duration. But the target must be attackable in order for this to continue or else it will interrupt this channel. It does not cleave.