pickup soul one time first, then activate the mega soul trainer, then go give soul to the tree
Yes. Its turn all material need to the same amount of souls needed to craft it.
You aren't supposed to turn it on and pick up souls. What everyone needs to do is pick up some souls activate the trainer, donate to the tree ONE TIME. and then disable. this will only give like 1mil souls and a single stack in your inventory. Otherwise when you go to build the bridge for fenrir you cant because your inventory shows its full of 1,000 stacks of 99k souls. Also this trainer only works on SOLO play survival and everything else is considered multiplayer so your stuff is stored there.