Atop his loyal steed - eh, atop his loyal wolf, Lex was suddenly reminded of the fact that even in his most desperate situation, he really wasn't alone. The nefarious system added all kinds of restrictions to prevent his escape to the Inn during a fight, but there was no such restriction on bringing in members of the Inn.
The moment he felt his connection to Fenrir restored, he did not hesitate to summon him over. Lex could instantly tell that Fenrir had grown much stronger, and from him Lex could feel an aura that was oddly similar to divine energy, though not quite.
The pup was momentarily startled by its sudden arrival on a battlefield, but it did not affect its performance. It had been fighting nonstop until its trial ended,and so it had really honed its instincts. Although a battlefield was a very different environment to fight in from a forest, the pup adapted quickly enough.