15 rexs with decent saddles a yuty 2 deaodons

Carry stimulant with you..., Cause they manticore can knock down Your dinos very fast in battle, and that will be your end

Make sure and bring a shotgun. If he ends up not landing enough its better to shoot him in the air and loose the element then not an loose everything.

Don't die

That's the best I can give you

Don't die

Alpha manticore gets absolutely melted by decent wyverns, even if you can only bring 11 with clever placing at the obelisk, and can probably still fit a yuty and some daedons.