First advice - move this to Cw part of forum. Amsodeo isnt available in regular Ap , since it`s mod for next game.
As for gameplay until getting Asmo to be sick tanky unit, you dont need to use only him. Get some archmages to spam magic shield (Asmo need resistances), thorns/royal thorns/cyclop to use target spell on them to spend enemy turns, and to pick up chests/mana balls from pet dragon ... If you use only him from start that can be very tiresome because he`s slow low on hp and dmg.
Kill enemy units using Asmo , but get some other units with you, some easy kept alive for support gathering role.
As for some practical info use pugmy on enemy as much as possible, somehow Asmo get more exp when attacking/killing enemy unit under pugmy. I have no idea why.
If you finish solo him, pls post screens with final stats ( i never got him to more then 40 lvl, got bored out of my mind soloing him all game

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