DISCLAIMER: My Xeno Xcalibur is unbalanced. And I also did some rematch battles. X2 did slightly better than before ;/
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(02/07/2018) Beyblade Burst Combo Testing:

X2 .7.Sp vs gV .6V.Rb
Score: 5-1 (gV wins)
Win Rate: 20-80

X2 .7.Sp vs dF .8.Nt
Score: 5-0 (dF wins)
Win Rate: 20-80

X2 .7.Sp vs nL .Ds
Score: 5-2 (nL wins)
Win Rate: 20-80

Total: 60/240
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X2. 7.X vs gV .6V.Rb
Score: 4-5 (X2 wins)
Win Rate: 50-50

X2 .7.X vs dF .8.Nt
Score: 3-5 (dF wins)
Win Rate: 40-60

X2 .7.X vs nL .Ds
Score: 2-5 (nL wins)
Win Rate: 20-80

Total: 110/240
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X2 .7.T vs gV .6V.Rb
Score: 5-2 (X2 wins)
Win Rate: 80-20

X2 .7.T vs dF .8.Nt
Score: 5-2 (X2 wins)
Win Rate: 60-40

X2 .7.T vs nL .Ds
Score: 2-5 (nL wins)
Win Rate: 20-80

Total: 160/240
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X2 .7V.T vs dF .8.Nt
Score: 5-1 (dF wins)
Win Rate: 20-80

X2 .7V.T vs nL .Ds
Score: 5-1 (nL wins)
Win Rate: 20-80

With Frame: 80/160
Without Frame: 40/160
———————
(Rematch Battles)
X2 .7.T vs dF .8.Nt
Score: 5-2 (X2 wins)
Win Rate: 60-40

X2 .7.T vs nL .Ds
Score: 5-3 (nL wins)
Win Rate: 40-60

Total: 100/160

Two things
Xeno Xcalibur is always unbalanced, that's just how it is
Testing against stock combos doesn't tell us anything (aside form Nightmare Longinus since it's so good in its stock combination)

Xeno is outclassed by most dual layers and some single layers. Some including L2, M, O2, and I2.

If you really want to use X2, add meteor or bump to it and see if it makes a difference.

Try a defense type.

Can you please test X2.1V/M/T.Ds? Thanks!