The phrase "as implacably as" is correct and usable in written English.
It can be used to compare the intensity or unyielding nature of two actions or feelings in a simile format.
Example: "She pursued her goals as implacably as a relentless storm, refusing to be deterred by any obstacles."
Alternatives: "as unyieldingly as" or "as relentlessly as".
And the John Birch right wingers hated him as implacably as their children do Obama.
Downton Abbey is bearing down upon the autumn TV schedules as implacably as the Red Army marching on Berlin, its advance preceded by a saturation media bombardment.
At 11am, against a background of pubs closing all over England (the CAMRA estimate is now 40 a week) – closing as implacably as the lights the Foreign Secretary Sir Edward Grey saw going out all over Europe in 1914 – the Old Red Lion was back in business in the Northamptonshire village of Litchborough.
But not even Goldwater had been as implacably opposed as a Democratic senator from West Virginia, Robert Byrd.
A glacier in Yosemite, its tracery sharply focused though seen from a remote height, is as implacably regular as the steel tracks being laid by the Union Pacific engineers.
They do not always agree with the United States, but they don't see it as implacably hostile or as an impediment to their own core objectives.
You describe Poppa Neutrino as "implacably restless," a nomad of sorts who has never lived in a house or an apartment for more than a year.
If Mohammad Davudi's haunting cinematography evokes that environment as implacably hostile, it also discovers the kind of toxic beauty found in Michelangelo Antonioni's "Red Desert".
No such devices are planned to help players who find their golf balls as implacably trapped in the high growth beside the 18 holes of the Royal Lytham & St. Annes Golf Club. Annes Golf Club
In 1941, the devils, which were originally seen as implacably vicious, became officially protected.
Related names that were used in the 19th century were Sarcophilus satanicus ("Satanic meatlover") and Diabolus ursinus ("ursine devil"), all due to early misconceptions of the devil as implacably vicious.
