Oops. I voted for Zone, but I miss read the question....
My real answer is "other".
Okay;
With Gengar:
This combo is a standard hit and run tactic just like the other. Hit for 60/80 and retreat back to the bench and lock the opponent. However, this combo has 2 flaws. A: Gengar takes three energy. B: Tomb is vulnerable to attacks.
With Zone:
This combo is used the same way the Gengar combo is; hit and run. The only difference here is that Zone is faster to power up and recharge when needed. The flaw here is the same as above; Vulnerable to attacks.
With "other":
This "other" would be Gliscor Lv X. This is also a hit and run deck, but it has more effect. By leveling up Gliscor, you paralyze and poison the opponent. Then you use Burning Poison to inflict another condition and return gliscor to your hand and bring up Tomb for the lock. Due to the conditions, they take damage AND cant attack or retreat.
This lock is much more potent. However, this too has flaws. A. Its power can be Power Sprayed. B. Leveling up Gliscor will only work each turn if you have a second gliscor ready and waiting.
For the Tomb only combo, Gliscor is probably the best. Followed by Zone.
For a Vileplume lock, Zone is best.
