Level 10
Paladin of Honor 2/Paladin of Freedom 2/Paladin of Slaughter 2/Paladin of Tyranny 2/Blackguard 2
Fort: +15 +(cha mod x5)
Ref: +0 +(cha mod x5)
Will: +0 +(cha mod x5)
[Cha 12-13 = +5, Cha 14-15 = +10, Cha 16-17 = +15, Cha 18-19 = +20, Cha 20-21 = +25, Cha 22-23 = +30, so on]
Base Attack Bonus: +10
Poison use
Lay on Hands equal to a 4th level paladin (total healing, Paladin levels x Cha mod/ or Paladin levels x [Cha mod x 2], pending on if you allow them to stack)
Deadly touch equal to a 4th level paladin (Same as lay on hands)
Access to 1st level Blackguard spells.
Normally i'd need to divide up stats to qualify for boneknight to get this sort of thing.
Logic for stacking: Corrupt Avenger's Grim Resolve; "Starting at 3rd level, you gain a bonus equal to your Charisma bonus (if any) on all saving throws. This benefit does not stack with other effects that allow you to add your Charsima bonus to saves (such as divine grace)." The exception proves the rule.
If there were variants of paladin for all alignments. at 20th level, without an alignment system, you could have x10 your charisma modifier to your saves. So, lets say you start out as a race that starts with +2 cha. You rolled an 18 for cha. Though your carrier you only added to cha, thats +5. So... Charisma 25, before item bonuses. Throw in a cloak of charisma (+6), thats 31. Add a Tome of Leadership and Influence (+5). We are at 36 Charisma. Under the x5 situation, we are looking at +65 to all saves. If you have a variant for every alignment, we are looking at a x10 situation, or... +130 to all saves.