He is a Legend Achievement - Space Hulk: Tactics - Exophase.com

Space Hulk: Tactics

Windows 10

1,866 Achievements Earned
585 Players Tracked
25 Total Achievements
16,455 Obtainable EXP
1,000 Gamerscore
8 100% Club

Win a mission with only one Terminator left alive

40

6.32% Very Rare - 562.00 EXP

You have not earned this achievement yet