War Beast's SotM effect is problematic for 3 reasons:
Routinely obsolete - The effect becomes completely useless while WB is transformed. It literally does nothing.
Decaying value - During mid/late game, the ult's cooldown becomes shorter, causing SotM's effect to have even less value as WB will be transformed more often.
Lack of synergy - Aside from bonus HP, the SotM effect provides mostly offensive bonuses when War Beast needs to be the most defensive (ultimate on cooldown).
Here is my suggestion:
War Beast
Metamorphosis - Staff of the Master effect change