Agreed
That’s one way of looking at it 
She’s an amazing 4* yellow hero.
Her mana delay pairs nicely even with the okay heroes like Chao and Li Xiu. -64% is a big delay in speed too – though not quite as good as Proteus, it lets you make off-color matches and fear little from enemy specials charging.
Her special skill defense debuff is not as good as Jackal’s, but it does stack with him and is easy to set up.
She’s overall the best yellow 4* hero in my opinion – tied with Jackal.
New status ailments introduced with Mist have been added to the Status Effects guide:
Note that a special skill defense buff can be overwritten by Mist’s special skill defense down debuff. The reverse is also true, so long as the target doesn’t have the buff block ailment (this can only happen when facing Monks – if the Monk withstands the buff block ailment but not the SS defense down)
Also note that the Buff Block status effect prevents buffs from overwriting negative ailments as well. For e.g. Sir Lancelot can’t overwrite the negative mana delay 
with his mana speed buff 
, since the buff block ailment prevents new buffs 
. However, Rigard and other cleansers can still dispel it.