Lol
[/b]PERFECT WIN[b]
as soon as you get the Spearton character, Max out his upgrades. Until then, max out your swordwraths. One spearton backed by 10 swordwraths (with the spearton under your control) is unstoppable.
To solo the last boss with a single spearton:
Max upgrade your spearton, take control of him, and attack the giant. Use Q to block just as he attacks (if your shield is maxed upgraded, you ALWAYS block when you hold Q). Attack during the giants cooldown. Rinse and repeat, and you win :D.
10/10 game btw