^That actually sounds pretty sick. Heatran's coverage and speed aren't incredible, but it has the power to hurt things extremely hard even with resisted fire blasts (lol +2 from Nasty Plot, maybe even picking up flash-fire aimed at Celebi), and subtitute is already an amazing move on even standard heatran sets. Plus, non-choice heatran is always liking items that let it fake being choiced (ie. no leftovers recover, LO damage etc. to blow the gig).
Then I thought how it's a pity that heatran is susceptible to thunderwaves, when I remembered something else sick about B-Pass Celebi.
Even if you are running a timid LO set, you can make slow passes by absorbing thunderwaves. By switching into thunderwave on something that loves to abuse the move, you can pick up the paralysis, making you slow, and then pass out safely after setting up, curing paralysis with natural cure and bringing your sweeper in without any fear of status.
Of course, that strategy would be bait if a Scizor switched in as you nasty plotted, but as long as we're imagining crazy celebi-based teams, you could always include a magnezone to take Scizor out before the action got started.
Hell, Sub-Salac Magnezone might be a ridiculous partner for Nasty-Plot-Pass Celebi anyway, again resisting Extreme Speed, Ice Shard and Bullet Punch.