Who do you recruit after the three legendary birds and how do you gain..

After you recruit the three legendary...Talk to Alakazam...Then he will tell you some stuff...After that go back to the Friend area of the Three Birds...You will get a some sort of gem..Then Silver Trench is now unlocked..

Talk to alakazam , then go to the legendary birds friend area talk to a bird now you can go to silver trench

Once you recruit the three legendary birds, go talk to Alakazam in the plaza. He will say something is going on in the birds' Friend Area. Go visit, they will combine their three powers together, and the Vortex Gem will be created! Congratulations!! You now have access to the Silver Trench!!

Apparently, after you recruit the three legendary birds, Lugia is next on your list. He is on the 99th floor. When you defeat him, he immediately recruits onto your team. He can use training, though........yeah. OK.

Hope I helped!!!

You can recuit any legenarys in the game there is no order and to unlock trecnh you have to visit someone then go to there friends area

Talk to alakasam in the square and he will ask you to go see what is wrong with the birds thus granting you access to silver trench

I do talk to alakasam. He says stuff about the lucario rank.

Complete pitfall valley