Weapons, spell damage, and momentum attack past GP. If they have something besides Tabuu and you have Gravity Pull, you can switch it to something else
But yes, overall, it does seem a bit much. Solution may be to set a limit to how delayed Tabuu can be, or set a limit to how much damage can be blocked. Idea: make Tabuu have to be one shotted, so buffs to health would increase damage limit. A balanced starting health could stay behind its attack so that paradox remains an option