Under the Speed Attack mode, Reiger's overall strength was slightly inferior to his own in the Strong Attack mode.
Therefore, in a contest of strength, Reiger, who had entered Speed Attack mode, could not compete with Gawain, a strength-type warrior. That Reiger would get knocked away like this was perfectly normal.
Speed alone, however, was far superior under the Speed Attack mode compared to the Strong Attack mode.
Thus, if Reiger wanted to defeat Gawain, he had to make good use of his speed advantage, rather than trying to outmatch Gawain in strength.
Which is to say...
"Avoid direct collision!"
Reiger, sent flying, nimbly adjusted his posture and landed on the ceiling in an upside-down stance, squatting there as if he were standing directly on the wall.
"Bang!"
The next second, Reiger shattered the ceiling, whipped up a shockwave, and like an arrow loosed from a bowstring, he cut through the space with astonishing speed and rushed above Gawain.