I've been an Ein main since DOA2 and thinking about how he played in DOA4 makes me think he'd be a heavy hitter and like CyberEvil said, single hit based and CB heavy (Like Akira, how bout that?) but I've been thinking about the technical side of things too after a little experimenting on DOA4 and this is what I feel he should have (if he didn't have some of these things already).
- 10 Frame jab.
- 2p should be +1 on hit
- Make 3p 13 frames.
- Either 6P+K or P+K should be his CB.
- F+K should cause a crumple stun on NH and a BT on CH.
- 3p, 6p, ppp, ppkk, 66pp, 46p, 236p, 66pk, 4ppp, 6kk, 4k, 1kk, 6F+KKK and P+KP should all be safe and 6P+K should be safe from a distance.
- 8p, 8k (1kk), 3k should all be sit-down stuns on CH and in stuns and chainable into CB (yes guaranteed CB combos just like Rig).
- 46k, 236k, 7p, 9pk, 4P+K and the last hit of 2kk (pp2kk) should all be guard breaks with advantage on block.
- 3p, 2(release)k, 4k and 9p should all be crushes.
- 2F+K (and all strings that end with it) should be a sit-down on CH and the 2nd hit of 2k2k (pp2k2k) should be a sit-down on NH.
- 6P+K, 3k and 6p should cause unholdable stuns in BT and chainable for a guaranteed BT combo.
- 33F+K should be unholdable.
- 236k, 4ppp and 33F+K should cause a ground bounce with guaranteed followups on NH and CH.
- 66kkk should remain a natural combo on CH.
- 7k should once again become a launcher.
- The last kick of all his pp6pk string variants should remain a mid kick.
Now the new stuff.
- 4pp, F+K, 2F+K, the last hit of all strings that end with k (66pk, etc), 4k, 33F+K and P+K should all be tracking moves.
- He should get a punch finisher to his 66kkk string (236p acting as the punch would work nicely).
- 3kkk should be a natural combo on CH.
- The last hit of hit 4ppp string should be a new sit-down stun (on both NH and CH) and a standalone move (214p)
- His sidesteps should be the last hit from 1kp for the punch and 2(release)k for the kick.
And potentially the most controversial of them all.
- He should keep his standing and crouching OHs.
For anyone unfamiliar with Ein's moves, this should cover anything and assure you everything I'm saying he should have is pretty reasonable.
Finally for the power blow, his charging animation should be a shoulder blow and once it hits you he should do 3p > 6p > 66kk and finally ending with a 236p or a more unique looking punch finisher.
...Yeah I've given this a lot of thought.