Colossal weapons ask more from the rest of the build than many faster weapon families. Their weight, stamina use and attack commitment mean Strength alone is not enough.
Build around the weapon weight
Check total equipment load before adding heavy armor on top of a heavy weapon. Endurance can support both stamina and the load budget needed to keep movement comfortable.
Use clear punish windows
Slow attacks are easiest after a boss finishes a long sequence. Do not force damage during short openings just because the weapon hits hard.
Stamina management
Leave enough stamina to dodge after attacking. A powerful hit is not useful if the attack consumes the entire bar and leaves no way to survive the response.
Strength is only one part of the plan
Vigor, Endurance, armor load and talismans can matter as much as another small increase in Strength. Use the Stat Planner to budget the full build rather than one offensive number.
When to switch weapons
If a particular boss gives almost no safe window for your current attack speed, a faster backup weapon can be more useful than rebuilding the whole character.