The mutation Initiative can be used to either leverage the high crit damage from tonfas' first attack or to compensate for the low damage from the following attacks in case of having missed the first attack.
Due to the 3 second cooldown of the Porcupack mutation, the Bladed Tonfas, while in the backpack will always be stuck on the first attack of the combo, and always deal critical damage (while obviously not flinging you forward)
Works well with Telluric Shock to push enemies just enough for the player to land the first attack and crit on them easily.
The tonfas struggle with hitting airborne targets, and so ranged weapons such as Throwing Knife and powers such as Lacerating Aura can greatly help it.
Notes
It is possible to turn around in the middle of the lunge and attack behind you when you land, a reversed attack makes the weapon hit much more consistently at close range.
The Lunge deals damage in front as well as under at the end of the first attack, so the distance you have to be from your target is not as far as you may think. Landing on your target is as viable as landing in front of them, as both will hit. This also means that you can land above your target and still hit them.
The first hit can no longer be a regular attack if the player was not moving during the attack. Initiating the leap attack no longer makes the rest of the combo deal 50% extra damage or need a speed buff to deal critical damage. Instead, the leaping attack makes the rest of the combo deal critical hits if it strikes the enemy.
Slightly reduced the crit damage, the damage of the fourth hit, and the duration of the first hit.
2.8: Updated description to reflect changes made in 2.7.1.