1.
sacrifice y2 Alpha
move r3 Castor Beta
move r3 Castor Beta
1...
sacrifice r1 Altair
attack r3 Beta
2.
attack r3 Beta
2...
sacrifice r1 Altair
attack r3 Beta
3.
attack r3 Beta
3...
sacrifice r1 Betelgeuse
attack r3 Beta
4.
attack r3 Beta
4...
build y1 Beta
5.
sacrifice r3 Beta
attack y1 Beta
attack y3 Beta
I composed this puzzle.