Build units that cover each other’s weaknesses. For example: Golem (tank, pierce dmg) + Pyro (magic dmg) covers waves 1–6 well.
A popular opener that can hold waves 1–3 without additional units. legion td guide
In late game (Waves 16-19), you should have demolished most T1 fighters and replaced them with T6 (Mythium) units. A board full of Snails and Grunts loses to a board of three Great Boars and four Elder Dragons . Build units that cover each other’s weaknesses
Defense is only half the game. If you never send mercenaries, you are playing a single-player game and will lose to anyone who pressures you. legion td guide