Tibalt or any planeswalker

[Bilygote]

Situation: My turn, 1st main phase, I have {Tibalt, the Fiend-Blooded} out with 6 loyalty counters. I activate his ultimate ability. He goes to the graveyard.

Combat occurs

2nd main phase, I play another {Tibalt, the Fiend-Blooded} and activate his +1 ability, etc...

The question arouse that since I activated the 1st {Tibalt, the Fiend-Blooded}'s ability I couldn't activate the 2nd one's ability

How should that play out?

I contended that since the 2nd {Tibalt, the Fiend-Blooded} was a new card that his abilities could be activated

[Keyeto]

You are correct. The new Tibalt has no connection to the first one, or whether or not its abilities are activated. It's a new card, and may activate its abilities.

[Rhazor]

Situation: My turn, 1st main phase, I have {Tibalt, the Fiend-Blooded} out with 6 loyalty counters. I activate his ultimate ability. He goes to the graveyard.

Combat occurs

2nd main phase, I play another {Tibalt, the Fiend-Blooded} and activate his +1 ability, etc...

The question arouse that since I activated the 1st {Tibalt, the Fiend-Blooded}'s ability I couldn't activate the 2nd one's ability

How should that play out?

I contended that since the 2nd {Tibalt, the Fiend-Blooded} was a new card that his abilities could be activated

MTG rules talk about the loyalty counters on that specific permanent, so you certainly can activate it in the second {Tibalt, the Fiend-Blooded}:

Each planeswalker has a number of loyalty abilities, which are activated abilities with loyalty symbols in their costs. Loyalty abilities follow special rules: A player may activate a loyalty ability of a permanent he or she controls any time he or she has priority and the stack is empty during a main phase of his or her turn, but only if none of that permanent's loyalty abilities have been activated that turn. See rule 606, "Loyalty Abilities."

(Source: http://media.wizards.com/images/magic/tcg/resources/rules/MagicCompRules_20130201.pdf)

RESOLVED

[Bilygote]

Thanks gentlemen, I just needed to confirm that my understanding of rule 606.3 was correct