• body blow, heavy blow, severe blow
• there'll be the devil to pay
• to bear hard on sy, to come hard on sy
• to meet with heavy losses, to suffer heavy losses, to sustain heavy losses
• pregnant with consequences
• desperate cases require desperate remedies
• to inflict heavy losses on the enemy
• grievously, onerously, sorely
• to aggravate, to exacerbate, to heighten, to sharpen, to swell, swelled, swollen
• gravity, massiveness, onerousness, ponderosity, ponderousness, seriousness