Now that his secret was out, Oli didn't care to hide his soul pressure within his dark-death essence. He purposefully showed off the might of his soul as Oli made a sharp change in his trajectory, throwing himself straight for the low-perennial.
That low-perennial had no soul art. But he could see what happened to the downed perennial and could easily recognize the strange pressure must've been from the drake's soul art.
With the perennial gorilla at his back and the mortal drake in front, the low-perennial assassin took the simplest, wisest bet. To defend and strike at the drake as fast as possible. Otherwise, with only water essence, the low-perennial might be slowed just enough for the gorilla to catch up.
The fiery early-perennial noticed what was happening as well. And a different set of options had been thrust upon him.