This is the 1-Angel Problem on a hexagonal grid, yes? <a href="http://llerrah.com/cattrap.htm" rel="nofollow">http://llerrah.com/cattrap.htm</a><p>Surprisingly tricky, even with a 1-angel!
Mathé's 2-Angel proof is really nice, or at least the summary is appealing -- he imagines a 'nice' devil, shows it can be beaten, then proves that if you can beat the nice devil, you can beat the mean one.<p>This is one of my favorite problem solving strategies -- reducing to a more obvious solvable situation, then filling in the chinks and gaps to expand back.