Certa, thanks for the note.
I played my own build of Gigas for States.
Went Top 8 in IL states, lost to vilegar(Ness) in swiss and sableye lock (Austin Z) in Top 8.
I think there was 4 other Gigas in IL, all different builds (surprise!), Big Chuck (Alex B), I think made cut but dropped with his.
WI states, was late with game loss, but went 4-2 remainder of swiss, losing to sableye (I misplayed my last turn, should have won) and dead hand lost to Magenzone. Still a solid deck. I will comment that I won many times on a Seeker Donk.
My list for WI.
4 2-2 Regigigas ( Promo's if you have them)
4 Mesprites
4 Uxie (1 Level X could work also)
1 Unown Q
2 Crobats
1-1 Mewtwo Lvl X (Tech spot)
1 Regice
3 ExBelt
4 Pokemon Collector
1 Dual Ball
1 Luxury Ball
4 Pokemon Communication
4 Drawer
4 Junk Arm
1 Warp Point (Agree on WP importance, maybe a 2nd)
1 Judge (This is over Giritina, which seems like a liability and bench target vs Luxuray and blaziken, Chomp, but that I will grant is debateable choice)
4 Seeker
2 Vs Seeker
4 Energy Search
2 Metal
2 Water
2 Fighting
3 Psychic (Match your tech line could be DCE too)
Easy to add different tech. And yes, my trainer line does make this build hard to beat full game trainer lock. Struggle versus Sableye with Hunchkrow SV when I played the Mewtwo. would try other tech line.