Spike's speed was superior to Yamcha but this doesn't count as speed is equalized this fight.
Both are bloodlusted so it's out of the question that Chara will let Spike talk and try and attack instantly, Spike may use either the trident or devilmite beam if he is bloodlusted so there are two possibilites
one: Spike will go for the trident and fall, this Chara was apparently from the battle with Undyne so there is no doubt it would be her undying form.. a stronger variation of Undyne who was capable of tanking a jump from a tall ledge in her base.
two: Spike will most likely go for the devilmite beam, now you may argue that Chara won't take much from the 'Karmic Retribution' of Spike here's Master Roshi's description of the devilmite beam: It is a force of unimaginable evil, that had destroyed more lives than any
war or pestilence combined. Long ago there was a
mighty-but-compassionate warrior. His power was beyond measure, yet many foolish upstarts tried to destroy him, in hopes of making a name for themselves. They were all unsuccessful, until one day, the Devilman appeared. Knowing he could not compete against the warrior's strength, the Devilman attacked using his mind. He discovered he could exploit his opponent's negative thoughts, no matter how faint, and convert them into an energy beam of immense power, the Devilmite Beam (Akkumaito Kousen). the devilmite beam basically latches onto even the smallest of dark thoughts and expands them into the targets heart, making it explode. the only use of this beam we saw was on Goku who was pure of heart thus making this attack useless and I don't know about you but a bloodlusted genocidal maniac ain't pure of heart to me.
so this battle will basically depend if Spike's capable of dodging Chara's first attack and firing a devilmite beam before the second strike
though if Chara can still fight even after losing their heart Spike is done for