An example of how the Unyielding Sentinel Epic Destiny could be expanded to level 10.
(And when the level cap goes to 30, it will need to be expanded to level 10
to grant caster level 30.)

Add more points available to level.
That would be 20 more points.

There are plenty of places to spend those points.

As far as the level 6 thru 10 inates, I can fill those in too.

6 Vigor of battle 2: Sentinel stance: grants +20% healing amp instead of 10% ; you gain +50 hit points

7 Hardened Unbreakable: Unbreakable Sentinel Stance now grants DR 15/--

8 Rock Strength you gain +10 physical resistance and +50 hit points

9 Rock Strength 2: +10 sacred bonus to natural armor

10 Stand Against the Tide 2: : Passive Bonus: additional +2 Attack.
Sentinel Stance: (Cooldown 20 seconds) +1 melee damage, 20% threat generation, 5% fort, +1 reflex/fort/will saves. These bonuses increases while standing still, up to 6 times instead of 4.