Wagner's Gravitational Time Dilation

You summon a temporal dilation causing time to move at a faster rate than normal for one or more targets.

When you cast this spell choose a willing creature that you can see within range to attach the dilation to. Until your next turn the target's speed is doubled, it gains a +2 bonus to AC, it has advantage on Dexterity saving throws, and it gains an additional action on each of its turns. That action can be used only to take the Attack (one weapon attack only), Dash, Disengage, Hide, or Use an Object action.

Every subsequent turn until the spell ends you can use a bonus action to attach the dilation to a willing target within 30ft.

When the spell ends, the caster must make a constitution spell saving throw with a DC of 12 + the level the spell was cast at.  If the caster fails the exertion of manipulating spacetime proves too taxing and it can't move or take actions until after its next turn, as the stress causes waves of pain to sweep over it.

At Higher Levels. When you cast this spell using a spell slot of 5th level or higher, you can effect one additional target for every two slot levels above 3rd.