Does a Pokémon's pre-mega ability matter if you only plan on using its mega?

[FreakyLocz14]

I plan on using Mega Alakazam. I have a Modest Abra I'm EV training, but it's ability is Inner Focus. I know Synchronize is generally considered to be the better option. I plan on only using Mega Alakazam, except maybe in the rare instance I know I outspeed and can OHKO my opponent if I don't want to give away the fact Zam is mega yet.

 

[Dragon]

I plan on using Mega Alakazam. I have a Modest Abra I'm EV training, but it's ability is Inner Focus. I know Synchronize is generally considered to be the better option. I plan on only using Mega Alakazam, except maybe in the rare instance I know I outspeed and can OHKO my opponent if I don't want to give away the fact Zam is mega yet.

It only really matters for certain Pokémon. For example, When you mega evolve a Sableye, you can still take advantage of its prankster ability to use a move like Will-o-Wisp first, while having Magic Bounce (its mega ability) at the same time.

Inner Focus and Synchronize are both situational but not really toooo important.

 

[5qwerty]

I plan on using Mega Alakazam. I have a Modest Abra I'm EV training, but it's ability is Inner Focus. I know Synchronize is generally considered to be the better option. I plan on only using Mega Alakazam, except maybe in the rare instance I know I outspeed and can OHKO my opponent if I don't want to give away the fact Zam is mega yet.

Well actually Magic Guard is the preferred option on most Alakazam. If you could get an HA Abra then it would probably be for the best, since you can avoid some hazard damage. Otherwise if Inner Focus is what you have then I guess there's not to much you can do about it except roll with it.

It only really matters for certain Pokémon. For example, When you mega evolve a Sableye, you can still take advantage of its prankster ability to use a move like Will-o-Wisp first, while having Magic Bounce (its mega ability) at the same time.

This is the case in Gen 6 games. This was changed in Gen 7 to automatically calculate the speed tier of the mega form upon evolution, which is why Sableye usually use Protect now, and why a lot of others (Diancie, Beedrill, etc) don't anymore.

 

[CrimsonMajestic]

It only really matters for certain Pokémon. For example, When you mega evolve a Sableye, you can still take advantage of its prankster ability to use a move like Will-o-Wisp first, while having Magic Bounce (its mega ability) at the same time.

Or Pokemon that can gain positive stat boosts or inflict stat decreases in a stat like Speed Boost (Sharpedo & Blaziken), Lightning Rod (Manectric), Moxie & Intimidate (Salamence, Gyarados, and Mawile (Intimidate only))