Let's go.
I have her for a while last year whlie I stealing borrow my friend account.
As a spoiler Saboten is the first knight I give S rank.
Why....?

She's quick. Very quick with 695 speed.

She has very low HP and can't recover herself, but she doesn't need it.
Because she can deal 5x double damage in every turn... at least almost.

The 60% re-act is very high in my real battle.
I saw her do double action in most of the fight.
Don't need to tell that if she active her skill what will happen.

She also has critical dmg & rate boost passive, in right place she will produce tons of damage.
And with a lot of adjustment now, it not that difficult to build around her at all compare to Red Ginger speed buff.

Her only down side in passive is the crystal drop passive that seem to be useless nowadays.
But with only 3 passive she already a monster.

Again she's S class knight.