This is what I came up with for Yukio, so far. Still tinkering.
"Yukio" (secret UltraRare subrace) - requires Half-Elf (changes Appearance)
DEX +4, CON -2, +10 spot, free feat: Martial Weapon Proficiency, free feat: Weapon Focus Longbow, free feat: Rapid Shot
Starting Stats (modified)
STR: 8
DEX: 16 (20)
CON: 18 (16)
WIS: 8
INT: 12
CHA: 8
01: Rogue(1): Luck of Heros
02: Rogue(2): {Evasion}
03: Rogue(3): Blind Fight, {Uncanny Dodge I}
04: Rogue(4): DEX+1, (DEX=21)
05: Rogue(5)
06: Rogue(6): Point Blank Shot
07: Rogue(7)
08: Rogue(8): DEX+1, (DEX=22)
09: Rogue(9): Great Fortitude
10: Rogue(10): Improved Evasion
11: Bard(1)
12: Arcane Archer(1): DEX+1, Iron Will, (DEX=23)
13: Arcane Archer(2)
14: Arcane Archer(3)
15: Arcane Archer(4): Toughness
16: Arcane Archer(5): DEX+1, (DEX=24)
17: Arcane Archer(6)
18: Arcane Archer(7): Improved Critical: Longbow
19: Arcane Archer(8)
20: Arcane Archer(9): DEX+1, (DEX=25)
21: Rogue(11): Great Dexterity I, (DEX=26)
22: Rogue(12)
23: Rogue(13): Defensive Roll
24: Rogue(14): DEX+1, Great Dexterity II, (DEX=28)
25: Rogue(15)
26: Rogue(16): Epic Dodge
27: Rogue(17): Great Dexterity III, (DEX=29)
28: Rogue(18): DEX+1, (DEX=30)
29: Rogue(19): Slippery Mind
30: Rogue(20): Epic Weapon Focus: Longbow
31: Rogue(21)
32: Rogue(22): DEX+1, (DEX=31)
33: Rogue(23): Self Concealment I
34: Rogue(24): Self Concealment II
35: Rogue(25)
36: Rogue(26): DEX+1, Self Concealment III, (DEX=32)
37: Rogue(27)
38: Rogue(28): Self Concealment IV
39: Rogue(29): Self Concealment V
40: Bard(2): DEX+1, (DEX=33)
41
42 Dex +1, Epic Skill Focus: Disable Traps
43
44 Dex +1
45 Epic Skill Focus: Search
46 Dex +1
47
48 Dex +1, Legendary Luck of Heroes
49
50 Dex +1
51 Legendary Will
52 Dex +1
53
54 Dex +1, Legendary Fort
55
56 Dex +1
57 Epic Prowess
58 Dex +1
59
60 Dex +1, (free slot - see below)
Still have a free feat at 60, and odd dex. So another Great Dex could work. But I'd like to get ESF: Discipline, so that would mean one fewer GrDexes somewhere, and I'm not sure what I'd replace it with.
Final saves at 60 were calculated at 67 Fort, 62 Will, 72 Reflex. If I DID go the ESF: Discipline route, and dropped a Greater Dex, I could pick up Epic Will, bringing everything up to snuff, at the cost of 1 AB, 1 AC, and 1 Reflex save (somewhat moot). (Note: this is from the CBC, not my own testing - I've found the CBC to be high on saves by 1 a few times, so these may be 66/61/71, but it's close)
HPs were low (as expected) at 418 naked @ 40.
I was able to max Concentration, Discipline, UMD, Search, Disable Trap, and Open Lock, putting 13 into Pickpocket.
I think it's a feasible build, and will probably start on it soon. Any feedback on this Chain? I don't mean to hijack your thread, and if you feel like I am, I'll remove my post. Just say the word. I was hoping to get some feedback from you, and maybe save you some time in the process.
Dex is a fair bit lower than yours, but that's somewhat to be expected, having to go Half-Elf over Elf, and losing some Dex being just a UR and not the BUR Erinyes (which I'd much prefer to do this with - but it's not meant to be, it seems).