Amarant can get 9999 hit points.

The highest possible strength for Amarant at Lv.99 is 84 (assuming you start levelling him from Lv.1 with the best equipment.)

Hp for a Lv.99 character = [(Strength * Hp Mod) / 50]

= [(84 * 4524) / 50]

= 7600

7600 + 10% + 20% (from the Hp+10% & Hp+20% abilities)

7600 * 1.1 = 8360.

8360 * 1.2 = 10032, capped at 9999.

That "find more posts from" feature is great.