Half giant mode, normal giant mode, incomplete version of giant 2.

1. Half-giant mode. When Allen was in the Survey Corps, because he could not completely control the power of the giant, when he achieved the purpose of grabbing the spoon and the pain, he transformed into two giants. After a few factors, he inadvertently transformed half of his body and hands into a giant.

2. Ordinary Titan mode, when Eren becomes the Attack Titan and the Ancestral Titan, he needs to first become an ordinary giant and devour those with the power of the Attack Titan and the Ancestral Titan before he can become a wise giant. And Allen, under his father's operation, successfully devoured his father and gained two major powers.

3. The incomplete version of Titan 2 is also the form that was created when Allen was not fully transformed into a giant due to some reasons.