Family Name: GreenShadowPT

Region (NA/EU): EU

Try this
Eat this (downsmash)
Twirl-Boom
Twirl-Three
And also Hop-Three and maybe Go!.

Where does it say you need down attacks/smashes?

The info says "a CC skill (regardless of type)"! Or with other words any skill with any CC effect can be used!

Thats not the issue. Did you read? The mobs gets knocked down to the ground, thats the issue.

Yes, they get knocked down to the ground if you use any cc effect on the leader, so they can be "easily" killed.
And you don't need to use a skill with down attack to knock them down, nore do you need it to attack them when they are on the ground!

What are you even saying? The entire mechanic is attacking the leader.

Clearly OP trying to say that class don't have any downattacks to take advantage of mobs behing knockdown to deal damage to them. I'm assume w/o bonus damage from downattacks OP have problems to grind that place, but that's Okay, as PA don't care about OP's class(maybe they actually do care, they just dont know about OP's class), they only care that mechanics works for latest and FOTM class, on a flat surface and stand still targets w/o target being obstructed by anything, like branch on pebble on the ground which will be focus fired by your skill instead of mobs!

And again:
If you use any CC skill (stun, stiffness, knockback, ...) on the Tehmelun Messenger all nearby monsters get knocked down and u get a buff to easily kill them!

Downattack is not required nore does it give you any bonus! The bonus comes from the buff!

In defense of OP, down attack gives a +50% damage modifier, before additional special damage buffs, on each hit on a skill with down attack. This is a lot of damage lost if using skills that do not have this modifier.

Shai, OPs class, has historically always been relatively weaker in spots where mobs can get CC'd, as Shai can take advantage of Back attacks, but not down attacks, while all other classes have down attacks. This is why Shai has been extremely strong in spots like Oluns / Trolls, as there you can get a lot of Back Attacks, while they have been weak at stars end for example (during the time where gear / class damage was not as high as it is now and people were forced to actually do the knockdown mechanic of the spot).

OP's request for down attacks for Shai is reasonable in so far as the class is getting a large cut in their damage compared to spots where mobs cannot be CC'd (most engame spots). 

Of course, the majority of damage comes from the buff, but the down attack still adds 50% damage on every hit, which is indeed a huge loss of damage if down attack is not applied.

lol you are clueless

when was the last time u did any pve content